ipad and iphone have different colors "assigned" to the same

Hi.
My icloud calendar colors match. They are both green.
But, for some reason, my Outlook Exchange (work) calendar is assigned a YELLOW dot on my ipad and BLUE dot on my iphone.
I have tried to change one of them, but I cannot.
I'd like them to be the same as they confuse me this way.
Is there a way I can DELETE one of them and re-install it as a different color?
Thanks,
My icloud calendar colors match. They are both green.
But, for some reason, my Outlook Exchange (work) calendar is assigned a YELLOW dot on my ipad and BLUE dot on my iphone.
I have tried to change one of them, but I cannot.
I'd like them to be the same as they confuse me this way.
Is there a way I can DELETE one of them and re-install it as a different color?
Thanks,