This was a popular style of photography in the 1970s, but I've seen it in the 80s & 90s as well.
These old fashioned color filters were actually created for analog black & white film photography. The color was meant to give the lens a better exposure for things like the sky in a black and white photo exposure or a "plate" because many cyan blue colors, like the sky are "nonrepro" and in essence the camera just can't see it, hence it wouldn't show on the film negative or on a "plate".
I know this because I had to study old school graphic art & "printing" in the 90s, in what we called "Advertising, Art, and Design" but I also studied the printer's end as well and did the photography, plate making, and even the work in the "dark room". I hated it because it stinks, and I have asthma, I'm also ADD and highly acute sensitive, which caused me to have migraines around the chemicals. At least the developing chemicals smelled more sour, but the inks' stench was head splitting and could be just as bad as inhaling gasoline. I didn't want to be a printer anyways, so they trained me to do "paste ups" with amberlith, rubber cement, and a drafting table. To this day I can still do many things manually, by hand, but all of those trades I just mentioned are NOW obsolete, and none of those skills can get me a job, and it's all digital.
Dust CAN BE CLEANED OFF. And, even the old stuff can be repaired, they just don't make things like they used to. I think I'd just scream & cry if somebody actually ever just handed me an old vintage Hasselblad and was like oh "Did you want this old thing?"! WOW.
Anyways, I got this old VIVITAR vintage filter from my father, along with his old vintage 1972 CANON FTB QL SLR! Love it!
So, I was experimenting with it once I got an adapter from 55mm to my 58mm lens.
This thing is GREAT! You can achieve different looks depending on the aperture.
I call these my New Ager Set