Added support for rgb color output.

[Remotion]

#include <fmt/colors.h>

int main() {
    std::tuple tup = {1, '1', "10", std::string("20"), std::string_view{"30"}};
    fmt::print("{}\n", tup);
    fmt::print(fmt::rgb(10,100,200),"{}\n", tup);
    fmt::print(fmt::rgb(200,100,200),"{}\n", tup);
    fmt::print(fmt::rgb(20,200,20),"{}\n", tup);
    fmt::print(fmt::rgb(20,0,250),"{}\n", tup);
}

[eliaskosunen]

This would probably be better as an enum class. Also, maybe rename it to something more descriptive, like color? I'm also not sure of the CamelCasing of the variants, and if it's consistent with the rest of the library.

[Remotion]

This would probably be better as an enum class.
Probably but I really do not want this to be too long.

fmt::print(fmt::Coral, "message {}\n", msg);
fmt::print(fmt::colors::Coral, "message {}\n", msg);

Also color names are from this list
Color Names Supported by All Browsers

Also Visual Studio and VS Code can directly show colors in the editor using this names.

Color Picker

VS Color Picker

Color Highlight

Unfortunately I could not find a way to support hex colors like #FFFFFF in C++.

Alternative would be to use color names like this, but this is even less readable.

    fmt::print(fmt::darkgoldenrod, "message {}\n", msg);
    // fmt::print(fmt::DarkGoldenRod, "message {}\n", msg);

[eliaskosunen]

What I meant was more like using snake_case instead of CamelCase since the library and C++ code in general tends to prefer the former over the latter. But you're right about those extensions, they seem to require the color names to be lowercase or CamelCase.

[vitaut]

I agree with @eliaskosunen's points that it should be a enum class color with snake case enum constants for consistency with the rest of the code:

enum class colors : uint32_t {
  alice_blue = ...
};

[vitaut]

Looks great. One minor comment inline and could you add a section to https://raw.githubusercontent.com/fmtlib/fmt/master/doc/api.rst describing this functionality in a separate PR.

[vitaut]

I agree with @eliaskosunen's points that it should be a enum class color with snake case enum constants for consistency with the rest of the code:

enum class colors : uint32_t {
  alice_blue = ...
};

[vitaut]

Merged with minor tweaks, thanks!