Read the numbers in the circles:
Normal Color Vision
Left Right
Top 25 29
Middle 45 56
Bottom 6 8
Red Green Color blind
Left Right
Top 25 Spots
Middle Spots 56
Bottom Spots Spots
Second test:
The individual with normal color vision will see a 5 revealed in the dot pattern.
An individual with Red/Green (the most common) color blindness will see a 2 revealed in the dots.