There is a bug in 7.x where if you are using multiple layers over the same area, the 2nd or top layer, defeats the lower layer. This only happens with a color adjustment, you can make exposure, contrast, sharpening etc, with no problems.
You are correct that Capture One works that way. Although it is an annoying limitation, it is a conscious design choice.
The thing is, the color editor works by editing an ICC profile. This has the advantage that we are able to control the colors *very* accurately, which was always the primary design goal of this tool. It does have several disadvantages; for example, it takes a whole lot of processing and memory when you move the sliders. It is also not feasible to "Embed camera profile" if you do layered color edits, because there is no way to express how these profiles should be merged on a pixel basis.
While we are able to create color profiles relative to edits performed on the background, this is not an option for multiple layers. What you really want is to "blend" the color edits pixel for pixel. While this is possible in theory, in practice it would require us to make a number of hacks to make it run at halfway decent speed. This, in turn, is really only possible if you are willing to give up some of the color accuracy of the tool.
While the choice can be debated, we chose accuracy of the edits as the first ten priorities. I agree that the resulting behavior may be a bit confusing, but I still think we made the most useful choice given the constraints.
If we can figure out a way to do it fast, without sacrificing color accuracy, we will reconsider it.
Esben H-R Myosotis