Color-specific filters

File: taj mahal filter.png (54KB, 396x453px) Image search: [Google]

54KB, 396x453px

yes. you can basically make any filter you want.

Specialised narrow bandpass-filters are redundant for scientific purposes (other types have been used for decades), and unused in general photography - only specialised niche imaging/research fields ever required them - as such, they're very hard/expensive to obtain.

The next best thing is fucking about with coloured filters from various devices, stained glass, you find this stuff in the weirdest places - i.e. I got a far infrared filter from a milsurp ir flashlight or an UV one from a tanning bed - and finding what works for your purposes, whatever they are. There's always dx.com's direct contact with chinese manufacturers - though they prefer to work in bulk, usually.