embedded subscripts / superscripts

[metcalfe]

I just upgraded to emacs-22.  When editing a (La)TeX file, it displays
subscripts and superscripts as such.  I'm having trouble, however,
with embedded sub/superscripts such as:
   \[ \|u\|_{L^p_tL^q_x} \]
In the above formula, the p,t,q,x are displayed in a very washed out,
nearly unreadable color.  Can somebody please advise how to set the
color for embedded sub/superscripts?  I was hoping to be able to avoid
turning off the rendering as raised/lowered text and/or changing the
background color so I can see the light color.

BTW, this is in the standard TeX mode (no AucTeX).

Thanks in advance.