Colours duplicating

[lemonyemily]

Recently I've started having a bunch of issues with the colours on my sprites. Pixels will seemingly randomly shift to a slightly different colour, usually indistinct from other pixels intended to be the same colour, but sometimes visibly different.
This appears to happen after a period of time, after which any action will cause a random selection of pixels to suddenly shift. However, some actions seem to more consistently produce this effect, such as importing a sprite. I am unsure whether this also happens when a sprite is exported (which would mean even manually fixing all affected pixels beforehand would be useless).
While it's difficult to notice with the naked eye, it's very annoying when trying to work with limited colour palettes, makes the fill tools basically useless, and completely clogs up the colour palette.

Steps to reproduce the bug

1. go to piskelapp.com
2. import a sprite or image and check the current colors palette
3. alternatively, start a new sprite from scratch and after a while any action will corrupt the palette

Environment details

• operating system: Windows 10
• browser (or offline application version): Firefox

Sprite details

The problem occurs regardless of frames or resolution. There does seem to be a period of time between each corruption (I'm not sure how long, though occasionally it happens while I'm in the middle of cleaning up the last corruption, so it doesn't seem consistent.), but imported sprites will be affected even if the session has only just started.

Compare the relatively small amount of colours that appear in the sprite with the amount shown in the palette on the bottom right.

[Xandr215]

piskel is dead. the last update to it was 2018.
cool strawberry pixel art though.