HSL color

The HSL color space is based on how humans perceive color, and as such, makes various aesthetically-pleasing color transformations very simple. Instead of saying how much light a monitor will emit (not a very natural way to think about colors), colors are described in terms of Hue, Saturation, and Lightness.

  • Hue describes where in the spectrum the color is. As Hue increases, a color will transition in the following order: Red, orange, yellow, green, teal, blue, violet, purple, magenta, red.
  • Saturation denotes how vibrant a color is. Ranges from grey to pure color.
  • Lightness is how light or dark a color is. Ranges from black to white. In the middle is either grey (if low saturation) or a color (if high saturation).

Here is a function Taehl wrote to convert HSL colors to RGB:

-- Converts HSL to RGB. (input and output range: 0 - 255)
function HSL(h, s, l, a)
	if s<=0 then return l,l,l,a end
	h, s, l = h/256*6, s/255, l/255
	local c = (1-math.abs(2*l-1))*s
	local x = (1-math.abs(h%2-1))*c
	local m,r,g,b = (l-.5*c), 0,0,0
	if h < 1     then r,g,b = c,x,0
	elseif h < 2 then r,g,b = x,c,0
	elseif h < 3 then r,g,b = 0,c,x
	elseif h < 4 then r,g,b = 0,x,c
	elseif h < 5 then r,g,b = x,0,c
	else              r,g,b = c,0,x
	end return (r+m)*255,(g+m)*255,(b+m)*255,a
end

This could be used, for example, like this: love.graphics.setColor(HSL(150,100,200)) (this would color things a greyish blue)


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