Yeah I agree with @CristianFilingeri I think it is important to maintain one, bright and recognizable channel icon, and it is important to keep that through your social media accounts. The channel banners should be updated from time to time, but the icon needs to be a memorable and recognizable for long-term purposes.
I've changed my profile picture twice I think. Considering it again. I've been doing this for 5 years and I believe my first profile picture (similar to this one) was my go to for about 2-3 years. Then I wanted a crisper more professional look, so I vectorised my display pic and I've been using it for maybe 2-3 years. The idea is for people to recognise you, and if you keep changing your display picture, people won't recognise you anymore. Like if McDonalds stopped using the M and instead had a clown face as their logo instead, the change would be confusing.