What color to paint fascia ?

Check the colorbond colours out. I would tend towards Manor Red, Deep Ocean, Ironstone or Woodland Grey.

I reckon it needs a light colour to cheer the place up. It looks,... well,... a bit sad at the moment, if you'll pardon me saying so. Mission brown tends to do that -- drags the feeling down (imho). Tastes vary, of course.

If you're game to try a lighter colour, maybe experiment with something like "Flower Center" half-tint (that's a Dulux colour, but any decent paint shop can probably mix it. Make sure you get the "exterior" variant -- if they're different formulas).

If your paint shop has a complete colour atlas (not just a "colour wall" which tend to be of little use), look through the subtle hues there and get some sample pots. Then you can experiment with half-tints and quarter-tints yourself. That's really the only way to achieve a happy result: find the right ballpark colour on small samples, then do a larger sample (e.g., a decent sized piece of 3mm mdf or whatever) so you can see what in looks like in the large.

Sometimes shifting the hue a bit is better. Sometimes "dirtying it up/down" works better. (By "dirtying", I mean adding some ochre or whatever -- a comprehensive colour atlas would already show such variants).

Adopting a good process (i.e., experimenting at length) is probably a wiser investment than any specific colour suggestions.

I would suggest painting it Paperbark to match your roof,this would help to "disappear "the fascia.
Regards,
Blocker.