This isn't that usual question . We have learnt to answer in our primary schools days , with a lot of childish pride .
It's more than that . It goes far to the early Islam civilization and was
associated with a horrible pandemic the spread among big Islamic cities at that time .
The face of a sick person had 3 colors red , yellow and blue . As long as his face is red or yellow , there is hope for him to survive but if his face has the blue color , that's mean he is going to die .
The 17 hejrah century black death ended in away or another . Only one thing was kept from that time until today .
The greeting " what's your color " that most of people use instead of saying " how are you " without know the connotations that stands for this sentence .
So , what we will have from Corona pandemic . What legacy will be pass to the comming generations after a 1000 year from now .