When using the Plugin for verifying #179, after it had been fixed, I noticed the following:
Put this code into bla.txt:
'''
@startuml
box A #FF0000
participant A1
end box
box B #00FF00
participant B2
end box
box C #0000FF
participant C3
end box
@enduml
'''
Check the image and "copy" it:

Paste it into Paint:

blue and red are inverted
Other diagrams react similarly.
Other tools react similarly: I tried Microsoft Word, Chrome (using github to file this ticket), GIMP on Windows 11.
When using the Plugin for verifying #179, after it had been fixed, I noticed the following:
Put this code into bla.txt:
'''
@startuml
box A #FF0000
participant A1
end box
box B #00FF00
participant B2
end box
box C #0000FF
participant C3
end box
@enduml
'''
Check the image and "copy" it:

Paste it into Paint:

blue and red are inverted
Other diagrams react similarly.
Other tools react similarly: I tried Microsoft Word, Chrome (using github to file this ticket), GIMP on Windows 11.