If you ask them they will send you samples, at least they did to me.
I ask for the grey .8 gain screen with a sample of matte white and 1.4 gain to compare against. They also sent a piece of the grey .4 gain screen to.
The .8 grey screen looked good but dimmed the picture. The Matte white was nice and bright and had good colours. With the 1.4 at my viewing distance I could see the texture on the vinyl.
I also got samples from DRH screens and ended up getting a matte white roll up screen from them.
DRH also sell just the material.
As the screen I got has slight waves I'm thinking of cutting off the material and making my own frame anyway.
Colour filters can be bought from
SRB filters
I think they do Hoya but will also custom make their own filters for you.
HTH