Red Sveta,
It depends on the exact time-frame and also on the particular regiment. Up to and during the Second Afghan War (1878-1880) Bombay Infantry regiments wore a variety of different "bespoke" regimental pattern turbans, some of which happened to be solid colors, like the khaki turbans worn by the 1st Bombay Grenadiers. Later in the 1880s many wore khaki turbans in the field, as seen on the Perry "Bengal/Bombay Infantry" figures in their Sudan range.
RE: collars and cuffs, these were always in regimental colors. Some regiments were amalgamated or renamed and renumbered during the 1880s and 1890s, which usually resulted in changes to their uniform regulations.
If you have a particular Bombay Native Infantry regiment you want details for, feel free to post the regimental info here and I can check for you in my copy of the Carman Indian Army infantry uniform reference book. It's an imperfect source that doesn't always have answers, but it does have them most of the time.
In the meantime, here's a pic of my own 1st Bombay Grenadiers -- who fought at Maiwand -- which may be the unit you are trying to build using the newer Perry figures:
