Every "real" light is fake in a game..
All of it is graphic effects and you decide which one you use..
You could either make the graphics in an image creation program, or use things like blendmodes and/or webgl effects to get the result you want..
There are multiple ways to get the job done..
It's up to you to find the one that suits you and your project..
If your lights are static, going for the image creation is usually the best option, dynamic lighting requires a lot more planning and choices..