You can probably take the logic board out of a 475 and put it in your LC as a type of upgrade. I'm not 100% sure it will fit but it seems like it should.

I know the Quadra 605 (Another LC-style Mac) usually has enough VRAM to do thousands of colors at 1024x768. I took one VRAM card from a 605 and put it into a Performa 450 (LC III) and it had equal capability after that.

Note that you can't leave just 1 VRAM SIMM in a 605...