Inspired by rcaslis's excellent DishWasher dirty / clean sign, but I wanted something much smaller and compact. Other improvements include a snap-together design (glue is optional), and the cover surrounds the back and slider pieces, so multi-color printing layers do not show through on the sides in the final product.

Monoprice Select Mini

Yes

No

0.2mm

20%

All pieces are in a single STL file. If you want to do multi-color prints, then you can split the grouping and delete components for individual pieces. At 0.2mm resolution, I paused at layers 0.8mm and 1.8 mm on the slider (for a white-green-white layering), and at 1.2mm on the back piece (for a white-red layering). I used the free online ColorPrint tool to add these color-change pauses: http://www.prusaprinters.org/color-print/

Snap together and make sure all pieces slide that should, and don't that shouldn't. Trim / sand as needed. I added some glue for the final assembly, but make sure you don't add too much or it will squeeze inside and freeze your slider. I then cut a 3M adhesive sticker to size and stuck it to the dishwasher.

Want a different font? Perhaps a green check or thumbs up, and a red 'X' or thumbs down? Want it bigger or smaller? The design file is included with parametric variables for easy customizations.