Purple comb tips on cockerel?

[Stefrrr]

My cuckoo marans cockerel just started to show purple tips on his comb. Did I read somewhere that this could indicate a heart problem?
It just showed up yesterday. And he also had a really sudden change in personality. He’s been reserved and mellow and suddenly got aggressive yesterday when the flock was free ranging, and then this morning when I put greens in the run.
He’s a little over 8 months old.

 

[Aapomp831]

Where are you located in the world? That looks like frostbite. As far as the aggression goes, it’s normal for a rooster to start acting that way around 8 months; their hormones are raging as they approach sexual maturity.

 

[Stefrrr]

I’m in Olympia, Washington. Lows are in the mid 40s this time of year. The back part of his comb is also purple. Their coop is really well ventilated - it’s about 75 square feet within a 1000 square foot barn, so frostbite seems unlikely.

 

[Isaac 0]

To me, It doesn't look heart-related, nor does it look like he suffered from frostbite. With roosters, and especially with larger combs breeds there is often blue/purple-ish discoloration near the tips indicating lack of blood flow. Most of the roosters around here have discoloration near the tips.