Change all blue to green

[Sonja]

If I have an image that has plenty of a certain hex colour A in it, and I want to change all pixels of that colour to another hex colour B, how do I do that?

I want it to intelligently convert pixels of other colours, i.e. a colour that is half-grey half-A becomes half-grey half-B, a pixel that is transparentesque A becomes transparentesque B, and so on.

How do I do this on paint.net or possibly with any online tool available.

Sonja

[BoltBait]

Sounds like you need to use the Conditional Hue/Saturation plugin:

http://forums.getpaint.net/index.php?/topic/13003-

See the example pictures on that page.

[Ego Eram Reputo]

...or: Advanced Color Replacement.

Recolors every pixel a different amount based on how similar it is to the secondary color.