Is there a way to get the equivalent of a color in different blending modes?

Question

I have to make a button with some shadows using HTML/CSS and I've been provided with a PSD file, which has a shape of the button and some effects applied to it. One of the effects is an inner shadow.

And it's blending mode is Multiply. There is no such possibility to use blending modes in CSS, so I think the only way to make 100% copy of the button is to convert the colors from Multiply blending mode to Normal. I found the formula of the Multiply blending mode.

It is : Result Color = (Top Color) * (Bottom Color) /255

So maybe its possible to get the top color respectively?

(Top Color) = (Result Color) / (bottom color) / 255

I tried this but its not working for some reason.

Any ideas?

Answer 1

The easiest way would be to open up the PSD and use the colour picker tool to sample the pixels you're after, and use that colour for the inner shadow in CSS.

Answer 2

Your math is rusty. :) Your equation should read TC = RC * 255 / BC, else you'll end up with a radically different result.

That said, as Marc points out, the more straightforward approach is to use the eyedropper to pick a 3x3 or even a point value from the densest part of the shadow.