The Gamecube version not so much, but the PC port (which is based on the GC version) has been pretty thoroughly hacked with tons of mods.
I believe your comment about Ice Cap stage having the wrong colors was also due to the lighting, possibly not texture related. The DC original had a different lighting engine (called Lantern Engine) than the GC ports and those based on it. PC again has mods that restores this.
There's a complete Dreamcast conversion mod for PC that restores all of the original geometry, textures and other graphical features that were cut. There's even a mod to restore the original character models (I don't use it personally but a lot of people prefer those models). There's even mods to implement the original DC version's DLC content, and even beta elements such as the massively more expansive (and IMO vastly superior) pre-release version of Windy Valley.
You'll probably need to follow a number of guides to set it up. But the main program that you need is the SADX Mod Loader. It can download and install the mods for you and contains other options and tools.