Yes, but even insulation will heat up eventually due to conduction from the black shell. So, even if air movement will mean the black helmet can remain as cool as a white helmet at speed that effect won't happen if say you're stuck in a traffic jam, or you just want to leave your helmet on your bike while you eat lunch.
Here's what we all need--something that goes inside the helmet to keep you cooler
For my part, I travel not to go anywhere, but to go. I travel for travel's sake. The great affair is to move. Robert Louis Stevenson
Wuwei screwed with this post 06-13-2011 at 10:57 AM