Hello,

I expect you need something like color separating filters. Dielectric coating filters are cheap and works well. Do not heat at high average power. I used some with white light sources. You can find 1inch size in Thorlabs (FD1B, FD1G ...). The same filters 2inch sized (round and square)  are available in EdmundOptics.com (Additive and Subtractive Dichroic Color Filters: 46-139, 52-541...).

To decompose mid IR region look for long pass edge filters or Hot-Cold filters.