bootstrap-navbar-transparent.less

// Transparent navbar
//
// Reset transparent navbar basics
@navbar-transparent-color:                      transparent;
@navbar-transparent-bg:                         transparent;
@navbar-transparent-border:                     transparent;

// Transparent navbar links
@navbar-transparent-link-color:                 #fff;
@navbar-transparent-link-hover-color:           #fff;
@navbar-transparent-link-hover-bg:              transparent;
@navbar-transparent-link-active-color:          #fff;
@navbar-transparent-link-active-bg:             transparent;
@navbar-transparent-link-disabled-color:        #fff;
@navbar-transparent-link-disabled-bg:           transparent;

// Transparent navbar brand label
@navbar-transparent-brand-color:                #fff;
@navbar-transparent-brand-hover-color:          #fff;
@navbar-transparent-brand-hover-bg:             transparent;

// Transparent navbar search
// Normal navbar needs no special styles or vars
@navbar-transparent-search-bg:                  #fff;
@navbar-transparent-search-bg-focus:            #fff;
@navbar-transparent-search-border:              #fff;
@navbar-transparent-search-placeholder-color:   #fff;

// Transparent navbar toggle
@navbar-transparent-toggle-hover-bg:            transparent;
@navbar-transparent-toggle-icon-bar-bg:         #fff;
@navbar-transparent-toggle-border-color:        #fff;


// !custom

.navbar-transparent{
  .navbar-nav:hover a {
    opacity:0.8;
  }
  .navbar-nav:hover a:hover {
      opacity:1;
  }
}

// transparent navbar

.navbar-transparent {
  background-color: @navbar-transparent-bg;
  border-color: @navbar-transparent-border;

  .navbar-brand {
    color: @navbar-transparent-brand-color;
    &:hover,
    &:focus {
      color: @navbar-transparent-brand-hover-color;
      background-color: @navbar-transparent-brand-hover-bg;
    }
  }

  .navbar-text {
    color: @navbar-transparent-color;
  }

  .navbar-nav {
    > li > a {
      color: @navbar-transparent-link-color;

      &:hover,
      &:focus {
        color: @navbar-transparent-link-hover-color;
        background-color: @navbar-transparent-link-hover-bg;
      }
    }
    > .active > a {
      &,
      &:hover,
      &:focus {
        color: @navbar-transparent-link-active-color;
        background-color: @navbar-transparent-link-active-bg;
      }
    }
    > .disabled > a {
      &,
      &:hover,
      &:focus {
        color: @navbar-transparent-link-disabled-color;
        background-color: @navbar-transparent-link-disabled-bg;
      }
    }
  }

  // Darken the responsive nav toggle
  .navbar-toggle {
    border-color: @navbar-transparent-toggle-border-color;
    &:hover,
    &:focus {
      background-color: @navbar-transparent-toggle-hover-bg;
    }
    .icon-bar {
      background-color: @navbar-transparent-toggle-icon-bar-bg;
    }
  }

  .navbar-collapse,
  .navbar-form {
    border-color: darken(@navbar-transparent-bg, 7%);
  }

  // Dropdowns
  .navbar-nav {
    > .open > a {
      &,
      &:hover,
      &:focus {
        background-color: @navbar-transparent-link-active-bg;
        color: @navbar-transparent-link-active-color;
      }
    }
    > .dropdown > a:hover .caret {
      border-top-color: @navbar-transparent-link-hover-color;
      border-bottom-color: @navbar-transparent-link-hover-color;
    }
    > .dropdown > a .caret {
      border-top-color: @navbar-transparent-link-color;
      border-bottom-color: @navbar-transparent-link-color;
    }
    > .open > a {
      &,
      &:hover,
      &:focus {
        .caret {
          border-top-color: @navbar-transparent-link-active-color;
          border-bottom-color: @navbar-transparent-link-active-color;
        }
      }
    }

    @media (max-width: @screen-xs-max) {
      // Dropdowns get custom display
      .open .dropdown-menu {
        > .dropdown-header {
          border-color: @navbar-transparent-border;
        }
        > li > a {
          color: @navbar-transparent-link-color;
          &:hover,
          &:focus {
            color: @navbar-transparent-link-hover-color;
            background-color: @navbar-transparent-link-hover-bg;
          }
        }
        > .active > a {
          &,
          &:hover,
          &:focus {
            color: @navbar-transparent-link-active-color;
            background-color: @navbar-transparent-link-active-bg;
          }
        }
        > .disabled > a {
          &,
          &:hover,
          &:focus {
            color: @navbar-transparent-link-disabled-color;
            background-color: @navbar-transparent-link-disabled-bg;
          }
        }
      }
    }
  }

  .navbar-link {
    color: @navbar-transparent-link-color;
    &:hover {
      color: @navbar-transparent-link-hover-color;
    }
  }
}

bootstrap-navbar-white.less

// White navbar
//
// Reset white navbar basics
@navbar-white-color:                      #333;
@navbar-white-bg:                         #fff;
@navbar-white-border:                     transparent;

// White navbar links
@navbar-white-link-color:                 #333;
@navbar-white-link-hover-color:           @orange;
@navbar-white-link-hover-bg:              transparent;
@navbar-white-link-active-color:          #333;
@navbar-white-link-active-bg:             transparent;
@navbar-white-link-disabled-color:        #333;
@navbar-white-link-disabled-bg:           transparent;

// White navbar brand label
@navbar-white-brand-color:                #333;
@navbar-white-brand-hover-color:          #333;
@navbar-white-brand-hover-bg:             transparent;

// White navbar search
// Normal navbar needs no special styles or vars
@navbar-white-search-bg:                  #fff;
@navbar-white-search-bg-focus:            #fff;
@navbar-white-search-border:              #fff;
@navbar-white-search-placeholder-color:   #ccc;

// White navbar toggle
@navbar-white-toggle-hover-bg:            transparent;
@navbar-white-toggle-icon-bar-bg:         #ccc;
@navbar-white-toggle-border-color:        #ccc;

// white navbar

.navbar-white {
  background-color: @navbar-white-bg;
  border-color: @navbar-white-border;

  .navbar-brand {
    color: @navbar-white-brand-color;
    &:hover,
    &:focus {
      color: @navbar-white-brand-hover-color;
      background-color: @navbar-white-brand-hover-bg;
    }
  }

  .navbar-text {
    color: @navbar-white-color;
  }

  .navbar-nav {
    > li > a {
      color: @navbar-white-link-color;

      &:hover,
      &:focus {
        color: @navbar-white-link-hover-color;
        background-color: @navbar-white-link-hover-bg;
      }
    }
    > .active > a {
      &,
      &:hover,
      &:focus {
        color: @navbar-white-link-active-color;
        background-color: @navbar-white-link-active-bg;
      }
    }
    > .disabled > a {
      &,
      &:hover,
      &:focus {
        color: @navbar-white-link-disabled-color;
        background-color: @navbar-white-link-disabled-bg;
      }
    }
  }

  // Darken the responsive nav toggle
  .navbar-toggle {
    border-color: @navbar-white-toggle-border-color;
    &:hover,
    &:focus {
      background-color: @navbar-white-toggle-hover-bg;
    }
    .icon-bar {
      background-color: @navbar-white-toggle-icon-bar-bg;
    }
  }

  .navbar-collapse,
  .navbar-form {
    border-color: darken(@navbar-white-bg, 7%);
  }

  // Dropdowns
  .navbar-nav {
    > .open > a {
      &,
      &:hover,
      &:focus {
        background-color: @navbar-white-link-active-bg;
        color: @navbar-white-link-active-color;
      }
    }
    > .dropdown > a:hover .caret {
      border-top-color: @navbar-white-link-hover-color;
      border-bottom-color: @navbar-white-link-hover-color;
    }
    > .dropdown > a .caret {
      border-top-color: @navbar-white-link-color;
      border-bottom-color: @navbar-white-link-color;
    }
    > .open > a {
      &,
      &:hover,
      &:focus {
        .caret {
          border-top-color: @navbar-white-link-active-color;
          border-bottom-color: @navbar-white-link-active-color;
        }
      }
    }

    @media (max-width: @screen-xs-max) {
      // Dropdowns get custom display
      .open .dropdown-menu {
        > .dropdown-header {
          border-color: @navbar-white-border;
        }
        > li > a {
          color: @navbar-white-link-color;
          &:hover,
          &:focus {
            color: @navbar-white-link-hover-color;
            background-color: @navbar-white-link-hover-bg;
          }
        }
        > .active > a {
          &,
          &:hover,
          &:focus {
            color: @navbar-white-link-active-color;
            background-color: @navbar-white-link-active-bg;
          }
        }
        > .disabled > a {
          &,
          &:hover,
          &:focus {
            color: @navbar-white-link-disabled-color;
            background-color: @navbar-white-link-disabled-bg;
          }
        }
      }
    }
  }

  .navbar-link {
    color: @navbar-white-link-color;
    &:hover {
      color: @navbar-white-link-hover-color;
    }
  }
}

bootstrap-navbar.less

// Navbar default resets

body.body-navbar-fixed{
    margin-top: 50px;
}

.navbar {
    border-radius: 0;
    margin-bottom: 0;
    border: none;
    .nav{
        .brandon;
    }
    .navbar-toggle {
        margin-top: 7px;
    }
    .navbar-brand{
        position:absolute;
    }
}

.navbar-absolute{
    position:absolute;
    width: 100%;
}

// the navbar with the holstee logo

.navbar-brand-holstee{
    .fh-icon-holstee-logo{
        height: 20px;
        overflow: hidden;
        display: block;
        line-height: 0;
        font-size: 150px;
    }
    .navbar-brand:hover{
        color:@orange !important;
    }
}

// ensure that the nave and the logo don't collide

@media (max-width: @screen-md){
    .navbar-brand-holstee .navbar-nav > li > a {
        padding-left: 12px;
        padding-right: 12px;
    }
}

@media (max-width: @screen-sm){
    .navbar-brand-holstee .navbar-nav > li > a {
        padding-left: 6px;
        padding-right: 6px;
    }
}

// the navbar with the mindful-matters logo

.navbar-brand-mm{
    .navbar-brand{
        padding-top:4px;
        padding-bottom:4px;
    }
    .fh-icon-holsteeh{
        font-size: 25px !important;
        vertical-align: top;
        display: inline-block;
        padding-top: 7px;
    }
    &.navbar-white .navbar-brand .vr{
        border-right: 1px solid #999;
    }
    &.navbar-transparent .navbar-brand .vr{
        border-right: 1px solid #fff;
    }
    .vr{
        height: 29px;
        margin: 6px 10px;
        display: inline-block;
        vertical-align: top;
    }
    a.blog-link{
        vertical-align: top;
        display: inline-block;
        line-height: 16px;
        padding-top: 5px;
        .top{
            font-size: 14px;
            letter-spacing: 1px;
        }
        .bottom{
            font-size: 12px;
        }
    }
    &.navbar-transparent{
        a.blog-link,
        a.holstee-link,
        a.blog-link:hover,
        a.holstee-link:hover{
            color:#fff
        }
        .navbar-brand:hover a {
            opacity:0.8;
        }
        .navbar-brand:hover a:hover {
            opacity:1;
        }
    }
    &.navbar-white{
        a.blog-link,
        a.holstee-link{
            color:#333
        }
        a.blog-link:hover,
        a.holstee-link:hover{
            color:@orange;
        }
    }
}

// ensure that the nav and the logo don't collide

@media (max-width: @screen-md){
    .navbar-brand-mm .navbar-nav > li > a {
        padding-left: 9px;
        padding-right: 9px;
    }
}

@media (max-width: @screen-sm){
    .navbar-brand-mm .navbar-nav > li > a {
        padding-left: 4px;
        padding-right: 4px;
    }
}


@media (max-width: @grid-float-breakpoint){
    .navbar-transparent{
        .navbar-white !important;
        .navbar-brand .vr{
            border-right: 1px solid #999 !important;
        }
    }
}

@media (max-width: @grid-float-breakpoint){
    .navbar-transparent,
    .navbar-white{
        .container{
            padding-left:0px;
            padding-right:0px;
        }
        .navbar-nav > li > a {
            padding-left: 15px;
            padding-right: 15px;
        }
    }
}

li.special a{
    position:relative;
}

li.special a:after{
    color: #F00;
    font-size: 9px;
    position: absolute;
    top: 10px;
    right: 3px;
    content: 'new!'
}

nav .badge-simba{
    position: absolute;
    top: 10px;
    left: 51px;
    background:@orange;
}

Well, pretty good script with custom brand badge.
I've found some easy way with just custom css - default navbar customization.
.navbar-default { background-color:transparent !important; border-color:transparent; background-image:none; box-shadow:none; }
Ref : http://twitterbootstrap.org/bootstrap-navbar-background-color-transparent/