Make Clarion look a little bit like Visual studio. Install this clarion color scheme as "VSDark" and select it from Options-->IDE-->Appearance. Then, install the ClarionAddins SetTheme addin and apply the VSBlack theme from Options-->Clarion Addins-->Set IDE Theme.

VSDark.xml

<?xml version="1.0"?>
<AppearanceProperties xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema">
  <DockTabStripAppearance>
    <xGradientBegin>-13816528</xGradientBegin>
    <xGradientEnd>-13816528</xGradientEnd>
    <xTextColor>ControlDark</xTextColor>
  </DockTabStripAppearance>
  <DockPadTitleAppearance>
    <xActiveBackColorGradientBegin>-16745780</xActiveBackColorGradientBegin>
    <xActiveBackColorGradientEnd>-16745780</xActiveBackColorGradientEnd>
    <xActiveTextColor>-2039584</xActiveTextColor>
    <xInactiveBackColor>-10724252</xInactiveBackColor>
    <xInactiveTextColor>White</xInactiveTextColor>
  </DockPadTitleAppearance>
  <DockTabAppearance>
    <Active>
      <xGradientBegin>-16745780</xGradientBegin>
      <xGradientEnd>-16745780</xGradientEnd>
      <xEdgeColor>-16745780</xEdgeColor>
      <xTextColor>-1</xTextColor>
    </Active>
    <Inactive>
      <xGradientBegin>-13816528</xGradientBegin>
      <xGradientEnd>-13816528</xGradientEnd>
      <xTextColor>White</xTextColor>
      <xEdgeColor>-12632250</xEdgeColor>
    </Inactive>
    <PadActive>
      <xGradientBegin>-9539978</xGradientBegin>
      <xGradientEnd>-9539978</xGradientEnd>
      <xEdgeColor>-8487285</xEdgeColor>
      <xTextColor>-10066330</xTextColor>
    </PadActive>
    <PadHide>
      <xGradientBegin>-13816528</xGradientBegin>
      <xGradientEnd>-13816528</xGradientEnd>
      <xEdgeColor>-12632250</xEdgeColor>
      <xTextColor>-3092272</xTextColor>
    </PadHide>
    <PadHideOver>
      <xGradientBegin>-13816528</xGradientBegin>
      <xGradientEnd>-13816528</xGradientEnd>
      <xEdgeColor>-16745780</xEdgeColor>
      <xTextColor>-16745780</xTextColor>
    </PadHideOver>
  </DockTabAppearance>
  <ApplicationHeaderAppearance>
    <xGradientBegin>-1682213</xGradientBegin>
    <xGradientEnd>-1682213</xGradientEnd>
  </ApplicationHeaderAppearance>
  <StartPageAppearance>
    <xGradientBegin>-13664586</xGradientBegin>
    <xGradientEnd>-7225118</xGradientEnd>
    <xSecondaryColor>WhiteSmoke</xSecondaryColor>
    <xPrimaryColor>-2430209</xPrimaryColor>
    <xButtonImageColor>-12095075</xButtonImageColor>
    <xGridHeaderColor>ControlLight</xGridHeaderColor>
    <xGridBodyColor>ControlLightLight</xGridBodyColor>
    <xGridAltBodyColor>ControlLightLight</xGridAltBodyColor>
    <xGridLineColorr>ActiveBorder</xGridLineColorr>
    <xGridHoverColorr>GradientActiveCaption</xGridHoverColorr>
  </StartPageAppearance>
  <ButtonAppearance>
    <CheckedAppearance>
      <xBackground>-21697</xBackground>
      <xBorderHighlight>White</xBorderHighlight>
      <xGradientBegin>-12398</xGradientBegin>
      <xGradientEnd>-20663</xGradientEnd>
      <xGradientMiddle>-17047</xGradientMiddle>
      <xHighlight>White</xHighlight>
      <xPressedBackground>-223427</xPressedBackground>
      <xSelectedBackground>-223427</xSelectedBackground>
    </CheckedAppearance>
    <PressedAppearance>
      <xBorder>-291780</xBorder>
      <xBorderHighlight>White</xBorderHighlight>
      <xGradientBegin>-223427</xGradientBegin>
      <xGradientEnd>-18338</xGradientEnd>
      <xGradientMiddle>-21697</xGradientMiddle>
      <xHighlight>White</xHighlight>
    </PressedAppearance>
    <SelectedAppearance>
      <xBorder>-12698048</xBorder>
      <xBorderHighlight>-12698048</xBorderHighlight>
      <xGradientBegin>-12698048</xGradientBegin>
      <xGradientEnd>-12698048</xGradientEnd>
      <xGradientMiddle>-12698048</xGradientMiddle>
      <xHighlight>-12698048</xHighlight>
    </SelectedAppearance>
  </ButtonAppearance>
  <GripAppearance>
    <xDark>-13816528</xDark>
    <xLight>-13816528</xLight>
  </GripAppearance>
  <ImageMarginAppearance>
    <Normal>
      <xGradientBegin>-12698048</xGradientBegin>
      <xGradientEnd>-12698048</xGradientEnd>
      <xGradientMiddle>-12698048</xGradientMiddle>
    </Normal>
    <Revealed>
      <xGradientBegin>-12698048</xGradientBegin>
      <xGradientEnd>-12698048</xGradientEnd>
      <xGradientMiddle>-12698048</xGradientMiddle>
    </Revealed>
  </ImageMarginAppearance>
  <MenuItemAppearance>
    <xBorder>-16745780</xBorder>
    <xPressedGradientBegin>-1682213</xPressedGradientBegin>
    <xPressedGradientEnd>-1682213</xPressedGradientEnd>
    <xPressedGradientMiddle>-1682213</xPressedGradientMiddle>
    <xSelected>-16745780</xSelected>
    <xSelectedGradientBegin>-16745780</xSelectedGradientBegin>
    <xSelectedGradientEnd>-16745780</xSelectedGradientEnd>
  </MenuItemAppearance>
  <MenuStripAppearance>
    <xBorder>-12698048</xBorder>
    <xGradientBegin>-12698048</xGradientBegin>
    <xGradientEnd>-12698048</xGradientEnd>
  </MenuStripAppearance>
  <OverflowButtonAppearance>
    <xGradientBegin>MediumAquamarine</xGradientBegin>
    <xGradientEnd>Maroon</xGradientEnd>
    <xGradientMiddle>Maroon</xGradientMiddle>
  </OverflowButtonAppearance>
  <RaftingContainerAppearance>
    <xGradientBegin>-7213708</xGradientBegin>
    <xGradientEnd>-12698048</xGradientEnd>
  </RaftingContainerAppearance>
  <SeparatorAppearance>
    <xDark>-13421769</xDark>
    <xLight>-13421769</xLight>
  </SeparatorAppearance>
  <StatusStripAppearance>
    <xGradientBegin>-16745780</xGradientBegin>
    <xGradientEnd>-16745780</xGradientEnd>
  </StatusStripAppearance>
  <ToolStripAppearance>
    <xBorder>-13816528</xBorder>
    <xContentPanelGradientBegin>-13816528</xContentPanelGradientBegin>
    <xContentPanelGradientEnd>-13816528</xContentPanelGradientEnd>
    <xDropDownBackground>-13816528</xDropDownBackground>
    <xGradientBegin>-13816528</xGradientBegin>
    <xGradientEnd>-13816528</xGradientEnd>
    <xGradientMiddle>-13816528</xGradientMiddle>
    <xPanelGradientBegin>-13816528</xPanelGradientBegin>
    <xPanelGradientEnd>-13816528</xPanelGradientEnd>
  </ToolStripAppearance>
</AppearanceProperties>