Being colorblind is difficult but it is more concerning for someone who doesn't know that he/she is colorblind. Today I will tell you some tips for to determine whether that person is okay or not with his/her vision.
1# Use colorblind test online
With this one you have see a number and typing it in. After doing some answers it will reveal your results. To confirm your results are the same be sure to do another one.
2# Ask a friend to show different sets of colors.
Now this is another form of test where you do it in real life. Now ask your friend to show a color and then try to answer it. If you managed to distinguish from red to violet then you are probably don't have to worry about colorblindness.
3# Use a sheet to determine the type of colorblindness
With this one try to look at photo in the normal type and then match it with one from the three other types. Use this example to check which one you have.
Normal Vision - All colors can be seen with normaly
Deuteronomy - Only yellow colors can be seen and other colors will have darker shades of yellow.
Protanopia - Same as previous but red will be grayish instead
Tritanopia - Color shifts: green -> blue , yellow -> pink , pink -> red