Setting a glow on certain colors in texture materials

I wanted to know if I can take a single texture with multiple colors on it and make only certain colors glow on the material.
For instance, take the Tron suits.

Say the mesh is a single texture (instead of multiple textures), can I only make the blue lines glow and the rest stay as they are?
If it is possible, is it expensive on the system (CPU, GPU) to do that.

Thank you