There is no standard recipe for Chicken Tikka Masala, but most are variants of a tomato gravy (using puree or even ketchup) with cream or coconut cream and various common spices.
There doesn't seem to be much doubt but that Chicken Tikka Masala was invented in Britain back in the 70s, when - it is claimed - some Brit demanded some form of sauce on his standard Chicken Tikka. Apparently, the chef covered it in Campbell's tomato soup! If that story is true, you now know how to make it, assuming you have a basic Tikka recipe!
Click here for a possible "original" recipe.
A masala is a mix of spices. Tikka masala is a mix of spices for use in a tandoor oven. Adding a yoghurt to create a sauce leads to the wet sauce to coat the meat as a marinade, rather than a dry rub.
Cayenne, tumeric, chillies and some other coloured spices give it the red / orange colour.
Done properly - great. Tomato soup with a bit of chicken floating in it and some chili - not great.