Could SRFI 166 be updated to include the 8 bright ANSI colors? I'm
referring to SGR parameters 90-97, which are the same color as the bold
versions of colors 30-37. Presumably these would be named
`as-bright-red`, `as-bright-blue`, etc.

In some terminals, these are distinct from bold colors. (as-bright-red
x) would render in the same color as (as-bold (as-red x)), but without a
bold font. On platforms that do not support this distinction (Windows)
the bright colors could just be aliases for the bold colors.