System: Mac 10.6.2, Brain 184.108.40.206
Start with the default theme of dark blue. Add some thoughts and assign them types, and then assign text colors to types. For example, type A = red, B = green, C = blue.
Now change the theme to white.
BUG: The thought text changes to black, but if your pointer passes over a thought, its bubble fill turns the correct color.
In short, the light themes (LA Sunset, white, and Light Blue) turn text white and darks turn the text black.
This might be by design, but I am not in favor of it. I'm using colors for text that is hard to read on a colored background but would be perfect on white ... but for white the text color disappears!