Steps for minimal example:
- Open Ipe.
- Import pump.png
- Export png
The resulting png will have yellow pixels near the top of the pump and end of hose.
I can reproduce this problem both in the web version of Ipe (running in Zen - a fork of Firefox) and the Ipe flatpak running on nixos.

test.pdf

Pump icons created by Ylivdesign - Flaticon
Please let me know what other info I could provide to help.
Thank you!