Question

Actually i want that, suppose i have a colorcode #FF3366. How can i examine that it is lighter or darker?
Actually i want to create a textfield and when the font color of the textfield is changed to lighter color by a javascript then the background color of the textfield becomes darker autometically for showing the value of the text field clearly and vise versa.

Please help me.

Answer 1

This formula is from years ago, in the W3’s site, but I can’t locate the address.
It sorts rgb colors from darkest to lightest. Works fine with just 2…

function lumenSort(ac, bc){
    return ((ac[0]*299 + ac[1]*587 + ac[2]*114)/1000-
    (bc[0]*299 + bc[1]*587 + bc[2]*114)/1000);
}
var A= [[0, 0, 0], [255, 255, 255]].sort(lumenSort);
alert(A[0]+' is darker than '+A[1]);