Depending on what type of work you do, lighting gels are for either stylized looks (party gels) or they are for a conversion reasons (tungsten to daylight).
I stumbled upon a tool a while back and it is pretty handy. The tool is from Lee Filters website and it’s pretty handy. It helps you convert light sources using the Mirad shift value. Then you can save your selections as a PDF where they list light loss etc.