Test your Response time!
Click on "Start" first, and wait until the background color changes.
As soon as it changes, hit "stop!" Yes it takes a little time.
Change background color in:
deeppink
aliceblue
crimson
darkkhaki
cadetblue
darkorchid
coral
chocolate
mediumslateblue
tomato
darkslategray
limegreen
cornflowerblue
darkolivegreen