Did California in 1967 prohibit open carry to discriminate against blacks, unlike Michigan that still allows it in 2020? [closed]

I'm British, and was befuddled to see this picture on r/oddlyterrifying of lockdown protestors carrying guns right up to the Michigan's Governor office door. I then found this combined picture on r/Political_Revolution.

This Reddit comment stated

The Mulford Act of 1967, signed into law by Governor Ronald Reagan, prohibited open carry in the state of California. The law was passed a mere 6 weeks after Black Panthers staged an armed protest at the state capital.

That post hints that racism against blacks explains the difference in open carry laws between the two states. Is this true?