I suggest you take that SpriteFont file to your favorite image editor and set it to all the different colors you wish to use, to get as many SpriteFont files as colors you want, then add them all to the project, each one with the name of the color. (As you can't add animations to SpriteFonts unfortunately, which would make things easier).
That way you won't have to use effects and impact your game performances. Only the memory used.