Flash an enemy white?

Hey, I was wondering if anyone knows of a nice shader that is IOS friendly, that can allow me the ability to flash any sprite I have to white? I'd rather not double up my textures in this game by creating white versions of them, I'm sure their must be a shader or 2 out there that can achieve this look.

Right now I'm simply changing their color to red, but that end's up looking like mud, I'd rather bloom out the texture to white like every other mobile game seems to be able to do.

I know very little, however about shaders, or how to install them. I'm willing to learn, but first I need to be pointed in the right direction.

Thanks!

 

I found this thread, but while people were helpful in how to turn an renderer on and off...nobody really address how to make a 2d sprite flash "white" using a mobile shader!

http://forum.unity3d.com/threads/224086-Make-a-sprite-flash

 

Still cannot find a mobile friendly shader that can handle this. Surely someone can point me in the right direction.