How do I invert the colors of this image so the fill is grey and the background is transparent in Inkscape?
If this was the trivial case (=a white shape on a grey rectangle) it would be easy: Delete the rectangle and select grey fill to the white shape. Check, if this happens to be the case. If this is grouped, goto Object > Ungroup to release the group at first.
More obvious is that you have a hole in a grey rectangle and the white is the background color. In this case other background shapes can be seen through the hole:
An yellow rectangle is added to the background to check the situation
The hole is filled with the paint bucket tool. The current foreground color happens to be red, but that can be changed later
The red shape is dragged aside and it's fill color is changed to grey. Done.
How I made the grey shape: I copied your image to Inkscape and started Path > Trace Bitmap. I selected Mode=Single Scan, Treshold = 0.63 , Remove Background. The resulted black shape was dragged aside and its fill was changed to grey.
If the figure is a single path object with 2 sub-paths (the rectangular frame and the figures), then you can:
- Select the path object
- Do Path -> Break apart to separate the frame and the figures into 2 paths.
- Select the figures and change the fill color.
- Select the frame and delete it or change its color.
- If you want to keep frame and figure together, select both and group.