What this exercise trains
A colour word appears in a colour that may or may not match its meaning, and you answer yes or no before the timer runs down. Reading is automatic, so the mismatched trials force you to suppress the obvious answer.
This is a playable version of the Stroop task, described by John Ridley Stroop in 1935 and still used in cognitive research. The delay you feel on mismatched trials is the Stroop effect, and it measures inhibitory control rather than intelligence as such.
Training exercises are not a scored assessment. For a measured result across four reasoning domains, take the free IQ test, and see our methodology for how that score is worked out. More exercises are on the training page.