Kamehameha color modeling

[Ajijang2013]

I have made a kamehameha spell. When I fired the spell, the head was trigged to launch and the rest of the missle's color was brighten as it was sticked together. I want my missle head color's bright as the path. What should I do?

 

[Vinz]

Have a model equal in both head and tail in terms of lighting.