You're right.
It occurs as well with OSX 10.14.6.
It occurs if you click on text either in Inspector or in the canvas.
Does not occur with system color.
And you notice that
- select a custom color (red), not a system color
- when select attributed, the text is displayed in red both in canvas and Inspector (with large font)
- when you reopen, text is black in Inspector, but colored in canvas, until you reset it with the color picker just below attributed.
- after this, it does not crash.
But, if you set attributed first, no crash.
So it appears that when transitioning to attributed with a custom color set, something is not correctly initialized.
Did you file a bug ?
For those interested, a more complete crash report
Process: Xcode [96294]
Path: /Applications/Xcode11.3-beta.app/Contents/MacOS/Xcode
Identifier: com.apple.dt.Xcode
Version: 11.3 (15710)
Build Info: IDEFrameworks-15710000000000000~27
Code Type: X86-64 (Native)
Parent Process: ??? [1]
Responsible: Xcode [96294]
User ID: 501
Date/Time: 2019-12-06 16:52:46.234 +0100
OS Version: Mac OS X 10.14.6 (18G95)
Report Version: 12
Bridge OS Version: 3.0 (14Y904)
Anonymous UUID: CA86F88E-841A-B935-419B-D9C89834C6BC
Sleep/Wake UUID: 3BCEA3A5-7416-4549-900C-9DAD1FCC0F32
Time Awake Since Boot: 1700000 seconds
Time Since Wake: 1800 seconds
System Integrity Protection: enabled
Crashed Thread: 0 Dispatch queue: com.apple.main-thread
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Exception Note: EXC_CORPSE_NOTIFY
Application Specific Information:
ProductBuildVersion: 11C24b
UNCAUGHT EXCEPTION (NSInvalidArgumentException): -[IBUIColor colorUsingColorSpaceName:]: unrecognized selector sent to instance 0x7fd3ec8cbed0
UserInfo: (null)
Hints:
Backtrace:
0 __exceptionPreprocess (in CoreFoundation)
1 DVTFailureHintExceptionPreprocessor (in DVTFoundation)
2 objc_exception_throw (in libobjc.A.dylib)
3 -[NSObject(NSObject) __retain_OA] (in CoreFoundation)
4 ___forwarding___ (in CoreFoundation)
5 _CF_forwarding_prep_0 (in CoreFoundation)
6 -[NSTouchBarColorListPicker selectedColorKey] (in AppKit)
7 -[NSTouchBarColorListPicker _effectiveSelectedColorIndex] (in AppKit)
8 -[NSTouchBarColorListPicker _setCurrentColor:updateScrubber:] (in AppKit)
9 -[NSTouchBarColorListPicker setCurrentColor:] (in AppKit)
10 -[NSObject(NSKeyValueCoding) setValue:forKey:] (in Foundation)
11 -[NSObjectParameterBinder _updateObject:observedController:observedKeyPath:context:] (in AppKit)
12 NSKeyValueNotifyObserver (in Foundation)
13 NSKeyValueDidChange (in Foundation)
14 NSKeyValueDidChangeWithPerThreadPendingNotifications.llvm.5095408093534035264 (in Foundation)
15 -[NSTextTouchBarItemController setSelectedAttributesWithEnumrator:] (in AppKit)
16 -[NSTextView(NSTextView_TouchBar_API) updateTextTouchBarItems] (in AppKit)
17 -[NSTextView(NSSharing) setSelectedRanges:affinity:stillSelecting:] (in AppKit)
18 -[NSTextView mouseDown:] (in AppKit)
19 -[NSWindow(NSEventRouting) _handleMouseDownEvent:isDelayedEvent:] (in AppKit)
20 -[NSWindow(NSEventRouting) _reallySendEvent:isDelayedEvent:] (in AppKit)
21 -[NSWindow(NSEventRouting) sendEvent:] (in AppKit)
22 -[IDEWorkspaceWindow sendEvent:] (in IDEKit)
23 -[NSApplication(NSEvent) sendEvent:] (in AppKit)
24 -[IDEApplication sendEvent:] (in IDEKit)
25 -[NSApplication run] (in AppKit)
26 NSApplicationMain (in AppKit)
27 main (in Xcode)
28 start (in libdyld.dylib)