I am currtenly using a TCX with 24-bit color under 1.6.1. It's slow, but
it works. IIRC, some bits of the driver code must be changed to get it to
work correctly - that is, beyond changing the #define TCX_CG8.  I don't
reemember what the code changes were (figures), so I'll recompile a kernel
when I get the chance and let you know. I haven't tested 2.0 yet, so the
changes may have been made.

The only problem I've had with the CG8 emulation is that console messages
that pop up after the server is started will corrupt the display
backplane, and the area of screen where the message is diplayed becomes
greyscale.  So unless you divert ALL console messages to someplace, you
must run xconsole.

Oh, and again, it's slow. Hopefully someone will find TCX docs and add
acceleration in the future. Solaris will probably go open source before
that happens.