Need help with changin the colour of the bike

Hi Guys,

This is my first post. I own a karizma R Sports(2004 model) and its colour is greenish blue. Just like this one http://www.thetopbikes.com/Images/H/...-Karizma-1.jpg (however this one is not mine). Recently I met with an accident and its fairing is toatally damamged. Need to change the plastics including tail and visor.

Now the problem is that this colour is very rare and hard to find spare of this colour. So i decieded to change the colour of my bike to black.

My query is: is it leagal to change the colour of bike from that in the RC?
What are the legal procedures to change it? Please help.

Thanks,
Fibin