New panes should inherit the tab color of the active pane when they're split

[tnodet]

Windows Terminal version

1.22.11141.0

Windows build number

10.0.26100.4061

Other Software

No response

Steps to reproduce

1. Close all instances of Microsoft Terminal
2. Open a cmd prompt or Powershell
3. Run this command:

• CMD: wt new-tab -p "Windows PowerShell" --tabColor "#FF0000" --title "Hello World" ; split-pane -p "Windows PowerShell"
• Powershell: wt new-tab -p "Windows PowerShell" --tabColor "#FF0000" --title "Hello World" ; split-pane -p "Windows PowerShell"

Expected Behavior

The resulting tab in Terminal should have the correct title and color set from command line.

Actual Behavior

The resulting tab in Terminal has the default title and color (not the ones defined in the command line).

If you run the same commands but with a semicolon at the end:

• CMD: wt new-tab -p "Windows PowerShell" --tabColor "#FF0000" --title "Hello World" ; split-pane -p "Windows PowerShell" ;
• Powershell: wt new-tab -p "Windows PowerShell" --tabColor "#FF0000" --title "Hello World" ; split-pane -p "Windows PowerShell" ;
  Then the resulting tab in Terminal have the correct title and color set from command line (and in addition, it opens another default terminal tab).

This is also the case using "startupActions" inside settings.json`:

• ❌ bugged: "new-tab -p \"Windows PowerShell\" --tabColor \"#FF0000\" --title \"Hello World\" ; split-pane -p \"Windows PowerShell\""
• ✅ okay: "new-tab -p \"Windows PowerShell\" --tabColor \"#FF0000\" --title \"Hello World\" ; split-pane -p \"Windows PowerShell\" ;"

[tnodet]

Ok I realize now what's happening: the title and color are per pane, not per tab.
It wasn't showing because the focus falls on the second pane.
If I click in the first pane, then it changes the title and color of the tab.

So the workaround is to set the title and tabColor on every pane of the tab.

This behavior is a bit confusing IMO.
If not specified explicitely, I think new panes should have the same title and tabColor as their "parent" tab.

[DHowett]

Thanks for debugging this. I renamed the issue to track how we'd probably fix it, per your recommendation!