Uji kepantasan tindakbalas anda
Mula-mula klik "Start" kemudian tunggu sehingga latar belakang berubah warna. Apabila ia bertukar warna terus tekan "stop!"
Tukar warna background :
deeppink
aliceblue
crimson
darkkhaki
cadetblue
darkorchid
coral
chocolate
mediumslateblue
tomato
darkslategray
limegreen
cornflowerblue
darkolivegreen