Allow to set custom color per event

[georgehrke]

fixes #71

1.	2.

3.	4.

1. By default, it's just showing the calendar color (and no x button)
2. Color picker
3. Once the user selected a custom color, they can press the x button to go back to the calendar color
4. Read-only view

[georgehrke]

@tcitworld Should we just hide the color in read-only mode?

[tcitworld]

Not sure the themed illustration pic would be enough, so I think we should keep it for now.

Btw, the "x button" to reset the color is hard to find at the end of the line (and low contrast).

[georgehrke]

If i remove the double opacity from __info and just leave the opacity from the ActionButton itself, it looks like this:

Putting the X right next to the color looks a bit odd imho:

[tcitworld]

I think it makes more sense if it's a "reset" icon next to it.

[georgehrke]

We could use icon-history for that:

[raimund-schluessler]

How would it look with the color input being the full width? Then everything would be aligned.

[georgehrke]

How would it look with the color input being the full width? Then everything would be aligned.

I tried that, but that looks very weird.
It's way too big and dominant for a simple color-picker:

[tcitworld]

We could display the CSS color name aside the input since we have it (joking, don't do that).

What we have in #1614 (comment) seems fine to me.

[georgehrke]

I changed it to #1614 (comment)

[georgehrke]

@tcitworld Good to go? :)

[ghost]

When I change the color, it looks good on the day and week calendar views, but appears merely as a small colored dot on the month view. Being slightly color blind, the small dot is easy to miss. Can we change the background color on the month view, like we do on the day and week views?

[ChristophWurst]

@MartinConsultingServicesInc use the forums please https://help.nextcloud.com/c/apps/calendar/42