I read Feedback 50021 (Colour picker presets & Hex fields are not working on IDE) but I am unsure this is what I get.
The code below does not display the c default colors in the code below.
Dim c As Color
c = RGB(20,80,140)
c = SelectColor(c, "Select a Color")
I need it for a current project (and probably every SelectColor user) that may fall in the water if The way things are going (or I will trash the project if no contract).
I get that in Xojo 2015r1, verified on Xojo 2018r1.1 (on El Capitan).
Can you confirm that ? IS it a Xojo Bug or a macOS bug ?
Tried it in 2018r1.1 on macOS 10.13.5 and it works perfectly when I change the last line to
Dim result as Boolean = SelectColor(c, "Select a Color")
The numbers won’t match; but the colours should. Welcome to the exciting world of color profiles (and they suck).
Xojo has standardised on a Generic Color Space; where as the macOS allows for multiple profiles to be stored everywhere. Most of the time they don’t get in your way; but that time that they do is incredibly frustrating to track down.
As someone who does a lot of image manipulation; I certainly appreciate Xojo’s choice to use only one color profile through their framework. I recently had a hard time with a custom Core Image filter because of how Core Image handles color profiles.
I can make your numbers match for you; but then the colors won’t 
Thanks.
The default color (meant to be the contents of c) is black instead of c.
This is just the feedback color in c that is wrong at Color window open, but the selected color (once I set my RGB values is correct.
This was working sometimes ago (maybe many times ago).
Ulrich: I will check about the Boolean error above (this was not my actual code, so I may have done an error), but I do not think this interfere with the default Color in the window (since this is the returned value (Yes|No).
Yes, my code was correct:
Color_Bool = SelectColor(Custom_Color, "Select a Color")
In another window, I have the KeyDown event that is ignored, MouseDown who do not set the focus (draw the focus ring around the Canvas), but Paste works fine !
So, I was capable to wongly use an example in a simplecopy/paste 
I go back to the project.