General Calendar in stock app keeps changing its color

[Sister Owl]

Hi all!
I have a weird problem with built-in calendar app. I have three iCloud calendars, with different colors assigned to them. One of the calendars is 'green' but it keeps changing its color to blue on itself. Not that I hated blue color. I know this is such a minor thing, but— Why is this happening and how to fix it?

 

[Sister Owl]

I ask, I answer in case anybody else will have this problem.
Apparently, the color is set during creating calendar only, it's impossible to change it afterwards. I mean, when you try to change the color afterwards it just keeps resetting new color to the one that was assigned to calendar when it was first created. The issue is solved by creating new calendar of needed color, and deleting the old one.

I really hope they fixed this in iOS 7, this is ridiculous.

Thanks for help, Owl