I have noticed that there seems to be some issue with assets that are being exported, when some of those have multiple backgrounds with at least one of them having the blend-mode “lighten”.
It’s being exported incorrectly and even the export preview already shows the error. Only the “lighten” blend-modes are affected. Other layers have also some blend modes but they export correctly.
The bottom image is transparent, so the colors you are seeing are coming from the gray Figma background. If you set the layer to Normal instead of Pass Through you will see that when it can’t mix with the background, it becomes non-transparent.