The Bambu slicer does offer such a thing, the results vary depending on the colors in question though, if the color it’s purging is black, and most of the print is white, then the black that gets flushed into the infill is going to be pretty visible under the white outer walls. This can be mitigated by thicker walls, and ofc its less of an issue when dealing with colors of different, but similar, shades

I’ve found that the best way to reduce multicolor waste is to try and setup your model in the first place so that it uses the smallest number of color changes possible, but ofc whether or not you have much control over that will depend largely on the model in question