Get any colour from linear gradient (default red to green with nice internal steps and no dirty brownish values)

gradient_colours.scss

// Rate of the most right colour. 10 points for green
$max_rate: 10;

/*
  Calculate colour between two values.
  $rate - required position
  $cmax - maximal value (0-255)
  $cmin - minimal value (0-255)
*/
@function _newval($rate, $cmax, $cmin) {
  @return $cmin + ($rate * ($cmax - $cmin) / $max_rate);
}

/*
  Get colour
  $rate - position in gradient from 0 to $max_rate
  $gradient - list of colours. I made it pretty simple so all steps are on the same distance from each other
*/
@function gradval($rate, $gradient: null) {
  $gradient: (#ff7676, #ffb25f, #f5f365, #bff36e, #89f278) !default;
  $max_step: length($gradient) - 1;
  // current position
  $current_step: $rate * $max_step / $max_rate;
  // right colour
  $cmax: null !default;
  // index of right colour
  $imax: 1 !default;
  // left colour
  $cmin: null !default;
  // index of left colour
  $imin: 1 !default;
  // result
  $color: nth($gradient, 1) !default;
  
  // trivail cases with 0 and $max_rate rates
  @if $rate == 0 {
    @return nth($gradient, 1);
  } @else { @if $rate == $max_rate {
    @return nth($gradient, $max_step + 1);
  }}
  
  // calculating indexes of the closest to $current_step colours
  @if floor($current_step) == $current_step {
    $imin: $current_step ;
    $imax: $current_step + 1;
  } @else {
    $imin: floor($current_step);
    $imax: ceil($current_step);
  }
  
  $cmax: nth($gradient, $imax + 1);
  $cmin: nth($gradient, $imin + 1);
  
  $r: _newval($rate, red($cmax), red($cmin));
  $g: _newval($rate, green($cmax), green($cmin));
  $b: _newval($rate, blue($cmax), blue($cmin));
  
  $color: rgb($r, $g, $b);
  
  @return $color;
}