Changing the ... um, er . . . hue of texture colors?

[The Mouth of Sauron]

I don't know exactly how to word this but, is there a way in Photoshop or something to do something like this:

Let's take that crappy blue hood in the smithy store. If I could open up the texture file in Photoshop, is there a way to go over it and make it white by telling the program to change all blue colors to white? I'm really not sure if I'm making myself clear, but I have no artistic abilities whatsoever, and I know I can't make a new texture myself.

 

[Khalid ibn Walid]

Replace color command. Or the Hue/saturation command. (to get white, best to desaturate first).

All that stuff under Image->Adjustments in Photoshop