Replacing color with transparency?

is it possible to select a color and replace it with transparency?


What is the application… ? what do you hope to achieve… a transparent gif or what…?
In photoshop select color range and delete, you may need to clean and soften the edges after this opperation as long as you have a transparent background this should be fine…
… But like I said what is the application?

I don’t really get what you want to do; but here’s what can possibly be done:

go to the channels tab, select your color channel (rgb or cmyk), select all, edit>copy

new layer mask, alt click the layer, and paste…

dunno if it’s what you want though…