This is an artwork I did like… years ago. Maybe it was on Photoshop, I don't remember. 

Anyway, this one came out not so bad, I'm quite happy with the result.

Swap Instructions:
Start with Black
At layer #5 (0.48mm) swap to Red
At layer #8 (0.72mm) swap to Yellow
At layer #12 (1.04mm) swap to White for the rest.

Filaments Used:
PLA+ eSun Black Transmission Distance: 1
PLA+ eSun Red Transmission Distance: 3.5
PLA+ eSun Gold Transmission Distance: 5
PLA+ eSun White Transmission Distance: 5