The test, titled 'Is my blue your blue?' shows a series of different shades, and simply asks whether you think each is blue or green. So, how does your colour perception compare to the rest of the ...

The three circles drawn in this photo seem like they are different shades of blue, but are in fact all the same color. Lenstore While many mind-blowing optical illusions can play with your brain ...

So it is no surprise to see a little online test go viral based on the very arbitrary demarcation between blue and green. Sure, navy and forest are very different shades. So are emerald and sapphire.

All of them performed a task in which they had to distinguish between different shades of blue on a scale of 1 to 20. They performed the task with and without a verbal interference task ...