Comment 6 for bug 913618

Yes the 0x4 bit is available (and in use on MIPS for the 3rd
"other endian" architecture.

The "preferred" color is settable through a macro. With 3 color bits,
the macro would need to become a list with 1st:2nd:3rd preference choices.

The ugliest part of H.J. Lu's patch is that the patch is propagating a useless "…()…"
marker in dependencies like

   Requires: libfoo.sp()(64bit)

With colors, the (64bit) is equally unnecessary because dependencies
match against other dependencies of the same color first. There are likely
consequences for depsolvers like polder which have never implemented
dependency (or file) colors correctly.