I bought Polymaker Purple to Pink thermochromic PLA. It changes color from purple (cold) → pink (just right) → white (too hot). Excellent for washing my dog. Just follow Prusa's recommendations for water tight printing:

• 3-4 perimeters
• raising the nozzle temp 5-10C over the presets
• extrusion-multiplier: increase this by 5-10 percent from default value / set line width 5-10% wider
• layer height 0.15mm, but 0.2mm will do

Note - it takes a minute or so for the temperature to change