Recently a post on LinkedIn titled "25% of the people have a 4th cone and see colors as they are ;p" by Professor Diana Derval has gone viral and probably because the "test" in the post tells a lot of people they are tetrachromats.
You see between 33 and 39 colors: you are a tetrachromat, like bees, and have 4 types of cones (in the purple/blue, green, red plus yellow area). You are irritated by yellow, so this color will be nowhere to be found in your wardrobe. 25% of the population is tetrachromat.
Tetrachromacy is a condition involving a forth type of cone cell in the eye that may allow some humans to see more colors. In reality scientists have confirmed this condition in only a few people. Scientists are not sure how many people have it, but an online test for it is simply not possible with current monitors.
As the FAQ at Newcastle University's Tetrachromacy Project says:
Q: Is there an online test that I can do?
A: Unfortunately, computer screens do not provide enough colour information to be able to ‘tap into’ the extra dimension that tetrachromats may possess. It is therefore impossible for an online test to investigate tetrachromacy.
The test in the LinkedIn post is a mediocre version of a color sensitivity test on the RGB spectrum. If you want to take a good version, this one is excellent. But if you do well on it, it does not mean you have tetrachromacy.