As the title says.
In the Decal/Livery/Design Editor, the opacity for each individual shape can be adjusted by a slider. This is all well and good but overlapping shapes (for example, both squares with opacity of 50%) creates errors in the design.
To simulate a consistent 50% opacity in a complex decal group, we’d need to layer a 50% opacity shape on top of it matching the base color of the car. Using masks is also no good as it completely hides the shape, and mask opacity cannot be adjusted either.
Adding an opacity slider for the decal/mask group would greatly improve design quality for all designers/creators in the upcoming game.