Textures have always seem brighter in Wally to me but they will look darker ingame, depending on your gamma settings. If you're familiar with the free graphics editor 'The Gimp', try following this old tutorial, it explains how to create and use your own Q2 palette for it.http://maps.rcmd.org/tutorials/q2_palette_textures/#converting_textures
Can you please direct me to quake2.pal ?
Step 1: Importing the Quake 2 palette into GIMP
http://tastyspleen.net/
http://tastyspleen.net/~quake2/baseq2/players/male/