Does anyone know why AdSense ad titles default to black?

Trying to use AdSense again (have not used it for a couple years), and I've noticed that no matter what text color I choose the ads show it as black. Any reason for that?

 

each years ctr & RPM are decreased,
its because more publishers & maybe lower adwords ads, because now there is more adwords competitors like fb ads

i think to survive google really want decreased the CTR for all publishers, so they do this

what do you think guys?

 

So, nobody knows?

For instance go to joboptimist.com and click on the Search Jobs button. The AdSense ad titles will be in black (in Chrome, FF, Opera). On a rare occasion I see blue titles on my cell phone. The font color I chose is #0026D3.

This is just weird.

 

I only see image ads on the above site, and they layout seems perfect. All the best

 

A couple weeks after posted this thread I changed them to image only. They are image/text ads now. They still show black titles. I just don't question it anymore. Whatever.