The testing methodology is quite flawed (at least for the reading speed test on the site). It asks you to read a passage with BeeReader to start out. When you're done, you're presented with questions about the passage before reading a non-BeeReader passage.
The catch is, you will almost certainly read the second passage slower than the first, since you're now looking to retain information for the questions!
The colored passages _feel_ faster, but I'm not sure that counts for much.
It did tell you it was gonna ask questions. Anecdotally I read the second paragraph faster because I had an idea of the difficulty-level of the questions involved. (ie not very)
The catch is, you will almost certainly read the second passage slower than the first, since you're now looking to retain information for the questions!
The colored passages _feel_ faster, but I'm not sure that counts for much.