Have you tried to change the Vertex Colors of the lights?
Should be the same thing as this: I use BitmapFonts (bright grey masked Texture/Brush) in a single surface system and color them by changing the Vertex Colors and adding Brush effects (fullbright shininess).
You would need one Texture only and could change the colors (red yellow white) as you need them from very bright to dark.
Should be the same thing as this: I use BitmapFonts (bright grey masked Texture/Brush) in a single surface system and color them by changing the Vertex Colors and adding Brush effects (fullbright shininess).
You would need one Texture only and could change the colors (red yellow white) as you need them from very bright to dark.