Change filament at layer is disabled while printing multicolor prints

I have a 2 color print that I already sliced and the 2 colors appear nicely in the preview tab of the Bambu Studio.
What I would like now is to be able to change the filament at a specific layer to introduce the 3rd color in the print.
But the Change filament option is disabled now:

There is another way to disable the “Change Filament” at layer option by setting the “Print Sequence” to “By Object” - which I use a lot. I don’t understand why this happens. This setting also blocks the “Add Pause” and “Add custom G-code” options.

These are the options that I used:


Am I doing something wrong?

I have this same issue. We’re you able to find a solution?

Saw a comment from here that said this function only works if the sliced print is only one color. I cleared all the “color painting” I had done so that the object was one filament, sliced it, and then went to the preview tab and right clicked on the little circle with the plus sign and the “Change Filament” option WAS available to use. So their advice seems accurate.

“The “Change Filament” function on the layer slider actually only works if the entire plate has only one color.”
github com/bambulab/BambuStudio/issues/3229

It’s not exactly true (unless you say “plate” when you meant “layer”), if you use only one color, the filament change appears but if you select it and print, it won’t stop at that layer because only one filament is chosen, you will need to add a pause for that. What happens is if you use AMS and do not select an entire layer to be another color, then bambu studio expect the whole print to be the same, so you cannot select change filament. The only way to have it appeared is to select full layer on different colors, then it works so painting and color change by layer cannot co-exist. This is certainly something that can be done but not implemented.

For the other issue, I think the print by objects remove the change filament capability because stopping, going to the chute, fill the prime tower at each color change etc can not be made without hitting one of the completed print or the prime tower. Again the software can be modified to take all this into account and move around objects but is certainly way too complicated for now and not even sure it makes sense to spend time on it given the size of the head and the size of the bed, it will be limited to small objects really far apart (and from the prime tower). May be it will make sense if bambu comes up with a bigger sized printer.