When editing surfaces, the base color of the material should be ignored

Here’s an example:
This is the uncolored carpet

Now watch me change the colors. The game doesn’t ignore the base orange-brown color scheme, it only adds the new colors on top

Yes this would be very nice. I hate broken floor colours ;-;

What you are seeing is a simple hue shift, and I think that changing the base color would require significant alteration of the texture itself, and as a result might be pretty difficult to implement with the current level of color customization.