Exhaust Color Differance

[1oldtimer]

Thought I would ask;
Is it normal that the right side exhaust be much darker than the left side?
I only ask because I cleaned the exhaust tips before I took a 670 mile ride down to Ga this past Tuesday and on my return home Friday, the right side was black compared to the left side being more on the brownish side. With the way the pipes are connected, I am assuming that this is normal. If not, maybe I need to pull the left baffle out and check for an obstruction..

Thanks,
Frank.