I've noticed that, in 3.40 OE-A, the default files have changing font colors, based on which theme you use. It's subtle, but each theme has a different font color, each very close to white, but it's noticeable. In some themes, I've swapped out only the system_plugin.rco, and ended up with different colors for each theme. That's enough evidence that there's some way to change the font colors using ONLY system_plugin.rco. My question is, how?