Don't let the complex versions put you down, the simplest formula is good enough, just Math.sqrt( Math.pow(L1-L2, 2) + Math.pow(a1-a2, 2) + Math.pow(b1-b2, 2) ).
Awesome, thanks for the advice. We were looking into alternatives for algorithms that better reflected human color interpretation, and that looks very helpful.
And yeah, your games are awesome, we basically modeled this as "the Kerning Game/Color Game, but for brands."
Don't let the complex versions put you down, the simplest formula is good enough, just Math.sqrt( Math.pow(L1-L2, 2) + Math.pow(a1-a2, 2) + Math.pow(b1-b2, 2) ).