Why do you have to wait so long to get your tattoo colored after you get it done?

Answer 1

If the outline is simple, you can color it in that same day.

Answer 2

You should wait until the tattoo has healed that can take about 2-4 weeks depending on how large your tattoo is. If you put new ink on a new tattoo, that can cause an infection. 

Answer 3

Because even when all the healing you can see is finished, there is healing you can't see that hasn't finished yet. 

Answer 4

you don't as it's up to you and the artist and you can start coloring it in after a week