I am working on an application that models physical hardware to the user. As such, showing things colored red seems to be a very natural way to communicate an error state, and showing them green indicates a successful state.
However, the client has mandated that the main color scheme for "accent" colors for the application be the triadic combination of Magenta, Yellow, and Cyan, like this (note that Color Scheme Designer seems to not work with Firefox right now but this link works fine in Chrome). As a side note, they have good reason for mandating those colors.
Because of this, I am concerned about a possible clashing effect if red and green are still used, since they will appear similar to the magenta and cyan respectively.
To try to maintain some design elegance (by limiting the number of accent colors used in the app), one approach could be to make the "success" and "error" colors be one of these three primary accent colors. I have tried this, but in my opinion these colors do not convey "success" and "error" as powerfully. So I wonder what research or experience has shown regarding still using red and green, even if those colors may have a slight clashing effect compared to your main accent colors. Does the benefit of the natural/expected meaning of red and green outweigh the possibility of some clashing with the main color scheme?
Update: (1) I will not be relying solely on colors to indicate state - iconography and such will also be used to indicate state. My question is strictly regarding the impact of the color choices. (2) These accent colors will be used fairly sparingly. However, it is possible that one of the accent colors would appear very close to one of the "success" or "error" colors.