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.