Add a convinence macro to create a color from a hex code / const function with comptime error

[A-Walrus]

What problem does this solve or what need does it fill?

Creating a color from a hex code. Alternative to having Color::hex("...").unwrap() (or Srgba::hex("...").unwrap())

What solution would you like?

Either:

• A macro to create a color from a hex code without unwraps, compile error if color is invalid.
• A const function with a compiletime error on invalid color, no need to unwrap

Not sure how this fits in with the new color overhaul :P

What alternative(s) have you considered?

Leave it as is.

[bushrat011899]

I believe the best solution to his problem, a const fn, is blocked by RFC #911. Once const float operations are permitted, I imagine almost the entire bevy_color crate could then by marked const.