I don’t have a favourite. Sometimes I buy colours that are gorgeous or ones that I don’t have. But sometimes I don’t.
But recently I bought an Emisar in black though I’ve been satisfied with the blue and green I’ve had so far and I could pick something special.
That pastel cyan looks nice on the new Noctigons, but if I had to choose for an arbitrary light, I’d take anthracite (some Jetbeams/OTRs have nice anthracite colors).
I prefer black, grey or dark silver lights. Alternatively clear from AL machining with lacquer.
A more unique approach would be to have a flashlight in the paint color of your personal car, but that is tricky to do I guess. Complex metallic paint probably difficult to put on a flashlight, but certainly possible.
I love the Cyan color on my Emisar D4SV2 but lately I like Olight’s Orange. Desert Tan is another color I like. Black is just to common and 95 percent of my torches are black. Astrolux Blue is nice as well.
Lotta nice colors out there. Jetbeam gray (like on the Jet-I and Jet-II) is nice. The deep blue, more like indigo, of the DV-S9 with the splash of red is pretty sharp. The slate-blue of the recent Skilhunt AAA is really nice. And I still like the Barbie Pink of the XTAR WK50, that was nice and satiny like granma candy.
It is definitely Silver (Convoy Clear ano. /C8+/, Astrolux Silver /MF01S/) for me. Maybe also darker greys, but still with a metallic shine.
Anything other (with color): Emisar/Noctigon cyan, pale blue or green, dark olive green, Astrolux blue or green, silver with a dark brass tinted cast (this is not yet seen, but I’d love it).