Print with 100% infill, 0.08 layer height and 0.16 base layer.

It is also advisable to reduce retraction to 0.6 mm.

Filaments used:

Bambulab PLA Basic Black with a transmission distance of 0.6.

Bambulab PLA Basic Red with a transmission distance of 4.0.

Bambulab PLA Basic Blue Gray with a transmission distance of 0.5.

Bambulab PLA Basic Beige with a transmission distance of 8.0.

Filament changes:

Let's start with black.

Change to red on layer no. 9.

Change to gray on layer no. 11.

Change to beige on layer no. 15 until the end.