I mostly wear WHITE t-shirts under my clothes....

[Death-Proof-69]

my belly button lint is exclusively dark blue and i almost always wear black t shirts..

 

[Vanilla Bear]

It's a combination of everything mixed together. Same goes for dryer lint.

Black shirts are usually made from blue fibers and dyes.

Aren't you a smarty farty?

I have never had lint in my belly button. This is intriguing.

You don't have a hairy belly, duh!