I know how that feels, same thing happened to our game, we get too used to how things work/look. I don't think keeping the color palette concise would contradict having visual clarity, if you use a different value of the same color I think it already fixes the problem without standing out too much. Grays and browns are usually very safe to use no matter the palette. In your specific case, a low saturation blue could have worked as well I believe. The colors overall were very good, but perhaps playing more with different saturation of the same color could have enhanced the visual experience. Just decided to mentions this here because I'm a full time artist so I have no idea how familiar with color theory and the like the people who also code are.