Steps to Reproduce:
Create two arrows of different colours.
Right-click and click on Line.
Change width of line under line properties.
Arrows turn white.
Arrows stay the same colours as before line width adjustment.
User Profile Reset: No
Changed the line width but not colours
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:55.0) Gecko/20100101 Firefox/55.0
Well, it changes the color to Automatic as you can observe in the dialog. When you create the arrow, the color is black.
This sort of thing is best handled with styles anyway, so I don't see there being a problem. Closing.
Re-opening. This is not best handled with styles, is not standard behaviour for any office suite, and is bizarre. Please don't mark as resolved when it is NOT
But how can you represent the multiple colours of the selected objects?
In the majority of applications, this is represented by having the property blank or in 'empty state' where the properties of multiple selected items conflict.
That way, if the user wants to change that property for all items they can, or if they are changing another property, it remains unaltered.
I mean - even Excel '97 does this... it's not like it's a new innovation here.. .
Ok, I guess we should strive for feature parity with MSO '97.
My gut feeling is that this would be quite a big renovation, so don't hold your breath for this being implemented any time soon.
Moreover, you can achieve what you want more robustly using styles right now, so you should just use them.
1. Create a main style for the general arrow shape and apply to all arrows (so you see the style in action)
2. Create child styles under the main style for colors (right-click the main style, New)
3. Apply color styles to arrows as you wish
4. Modify the main style to change the width or other properties for all the arrows at once
though for my scenario, I'm only dealing with individual slides, so it's unnecessary to create styles.
It was easier just to individually edit the lines- just slow.