LESS mixin for RGBA colours in IE

gistfile1.sass

// Use with colour name: .rgba(black, 0.5) or hex value: .rgba(#FF2400, 0.5)
.rgba(@colour, @alpha)
{
	@alphaColour: hsla(hue(@colour), saturation(@colour), lightness(@colour), @alpha);
	@ieAlphaColour: argb(@alphaColour);
	
	background-color: @colour; // Fallback for older browsers
	background-color: @alphaColour; 
	
	// IE hacks
	zoom: 1; // hasLayout
	background-color: transparent\9;
	-ms-filter: "progid:DXImageTransform.Microsoft.gradient(startColorstr=@{ieAlphaColour}, endColorstr=@{ieAlphaColour})"; // IE 8+
        filter:  ~"progid:DXImageTransform.Microsoft.gradient(startColorstr=@{ieAlphaColour}, endColorstr=@{ieAlphaColour})";  // IE 6 & 7 
	
}