You should not have to color your hair extensions if your match was done correctly. If you cannot find a true match then no, it is not recommend coloring your hair extensions. However if you have to get your roots retouched please visit a Hair Extensions specialist that is comfortable with coloring and Hair Extensions. If not you can risk damaging and destroying your hair extensions.
Color on the bonds can disintegrate them and shorten the lifetime of the extensions.
WARNING: DO NOT rinse hair with high salon jets as it may cause matting. And please be advised often times stylists will say they can do something just to get you in the chair.