starred/terminal
1
0
Fork 0
mirror of https://github.com/microsoft/terminal.git synced 2026-02-04 05:35:20 +00:00
Code Issues 19.0k Packages Projects Releases 20 Wiki Activity

[PR #19525] Fix color shift when terminal window is unfocused #31865

New Issue
Open
opened 2026-01-31 09:50:01 +00:00 by claunia · 0 comments
claunia commented 2026-01-31 09:50:01 +00:00
Owner
Copy Link

Original Pull Request: https://github.com/microsoft/terminal/pull/19525

State: closed
Merged: No

This PR fixes a visual bug where ANSI/VT colors (especially greys) visibly shift or flicker when Windows Terminal loses focus.
The issue occurs because ControlCore::ApplyAppearance() forces a full frame and background redraw even when the window is unfocused, causing unnecessary re-rendering and blending of colors.

What Changed

In ControlCore::ApplyAppearance():

Replaced:

TriggerRedrawAll(true, true);

With:

TriggerRedrawAll(focused, focused);

Meaning:

When the terminal is focused, behavior remains unchanged → full redraw.
When unfocused, redraw is limited to only what is required → prevents ANSI color flickering/dimming.

Why This Fix Works

Windows Terminal has “unfocused dimming / opacity adjustment” behavior.
By always forcing a full redraw (even when unfocused) the renderer was unnecessarily triggering color changes in RenderEngineBase, leading to visible flickering of greys and other ANSI colors.

By only forcing a full redraw when the control is actually focused, we:

Avoid redundant expensive paint operations
Preserve exact ANSI color output (no flicker, no dimming)
Maintain the intended behavior when unfocusedAppearance is explicitly configured**

Validation Steps

  1. Launch Terminal with PowerShell.

  2. Output large ANSI or color-heavy content:

    for ($i=0; $i -lt 24; $i++) { Write-Host ("Gray sample " + $i) -ForegroundColor Gray }

  3. Unfocus/minimize/alt-tab repeatedly.

  4. Before fix: colors shift between frames (visible flicker)

  5. After fix: colors remain stable while unfocused, no shifts

Tested with:

Default profile
Acrylic enabled / disabled
Custom unfocusedAppearance profile (to ensure feature still works)

Related Issue

Fixes #XXXXX
(Replace XXXXX with the issue number after creating the GitHub issue.)

Checklist

[x] Fixes unfocused color flickering issue
[x] No change to behavior when focused
[x] Does not break unfocusedAppearance feature
[ ] Closes #XXXXX
[ ] Tests added/passed (if needed)
[ ] Docs updated (if needed)

**Original Pull Request:** https://github.com/microsoft/terminal/pull/19525 **State:** closed **Merged:** No --- This PR fixes a visual bug where ANSI/VT colors (especially greys) visibly shift or flicker when Windows Terminal loses focus. The issue occurs because `ControlCore::ApplyAppearance()` forces a full frame and background redraw even when the window is unfocused, causing unnecessary re-rendering and blending of colors. What Changed In `ControlCore::ApplyAppearance()`: Replaced: TriggerRedrawAll(true, true); With: TriggerRedrawAll(focused, focused); Meaning: When the terminal is focused, behavior remains unchanged → full redraw. When unfocused, redraw is limited to only what is required → prevents ANSI color flickering/dimming. Why This Fix Works Windows Terminal has “unfocused dimming / opacity adjustment” behavior. By always forcing a full redraw (even when unfocused) the renderer was unnecessarily triggering color changes in RenderEngineBase, leading to visible flickering of greys and other ANSI colors. By only forcing a full redraw when the control is actually focused, we: Avoid redundant expensive paint operations Preserve exact ANSI color output (no flicker, no dimming) Maintain the intended behavior when unfocusedAppearance is explicitly configured** Validation Steps 1. Launch Terminal with PowerShell. 2. Output large ANSI or color-heavy content: for ($i=0; $i -lt 24; $i++) { Write-Host ("Gray sample " + $i) -ForegroundColor Gray } 3. Unfocus/minimize/alt-tab repeatedly. 4. Before fix: colors shift between frames (visible flicker) 5. After fix: colors remain stable while unfocused, no shifts Tested with: Default profile Acrylic enabled / disabled Custom unfocusedAppearance profile (to ensure feature still works) Related Issue Fixes #XXXXX (Replace XXXXX with the issue number after creating the GitHub issue.) Checklist [x] Fixes unfocused color flickering issue [x] No change to behavior when focused [x] Does not break `unfocusedAppearance` feature [ ] Closes #XXXXX [ ] Tests added/passed (if needed) [ ] Docs updated (if needed)
claunia added the pull-request label 2026-01-31 09:50:01 +00:00
Sign in to join this conversation.
No Branch/Tag Specified
Branches Tags
Labels
Clear labels
⛺ Reserved
A11yCO
A11yMAS
A11ySev1
A11ySev2
A11ySev3
A11yTTValidated
A11yUsable
A11yVoiceAccess
A11yWCAG
Area-Accessibility
Area-AtlasEngine
Area-AzureShell
Area-Build
Area-Build
Area-Chat
Area-CmdPal
Area-CodeHealth
Area-Commandline
Area-CookedRead
Area-DefApp
Area-Extensibility
Area-Fonts
Area-GroupPolicy
Area-i18n
Area-Input
Area-Interaction
Area-Interop
Area-Localization
Area-Output
Area-Performance
Area-Portable
Area-Quality
Area-Remoting
Area-Rendering
Area-Schema
Area-Server
Area-Settings
Area-SettingsUI
Area-ShellExtension
Area-ShellExtension
Area-ShellExtension
Area-Suggestions
Area-Suggestions
Area-TerminalConnection
Area-TerminalControl
Area-Theming
Area-UserInterface
Area-VT
Area-Windowing
Area-WPFControl
AutoMerge
Blocking-Ingestion
Culprit-Centennial
Culprit-WinUI
Disability-All
Disability-Blind
Disability-LowVision
Disability-Mobility
External-Blocked-WinUI3
Fixed
Gathering-Data
good first issue
HCL-E+D
HCL-WindowsTerminal
Help Wanted
Impact-Compatibility
Impact-Compliance
Impact-Correctness
Impact-Visual
In-PR
InclusionBacklog
InclusionBacklog-Windows TerminalWin32
InclusionCommitted-202206
Issue-Bug
Issue-Docs
Issue-Feature
Issue-Feature
Issue-Question
Issue-Samples
Issue-Scenario
Issue-Task
Needs-Attention
Needs-Author-Feedback
Needs-Bisect
Needs-Discussion
Needs-Repro
Needs-Tag-Fix
Needs-Tag-Fix
Needs-Triage
No-Recent-Activity
Priority-0
Priority-1
Priority-2
Priority-3
Product-Cmd.exe
Product-Colortool
Product-Colortool
Product-Colortool
Product-Conhost
Product-Conpty
Product-Meta
Product-Powershell
Product-Terminal
Product-WSL
pull-request
Mirrored from GitHub Pull Request
 Resolution-Answered
Resolution-By-Design
Resolution-Duplicate
Resolution-External
Resolution-Fix-Available
Resolution-Fix-Committed
Resolution-No-Repro
Resolution-Won't-Fix
Severity-Blocking
Severity-Crash
Severity-DataLoss
spam
this-will-be-a-breaking-change
Tracking-External
WindowsTerminal_Win32
Work-Item
zAskModeBug
zInbox-Bug
No Label pull-request
Milestone
No items
No Milestone
Projects
Clear projects
No project
Assignees
Clear assignees
claunia
No Assignees
1 Participants
Notifications
Due Date
No due date set.
Dependencies

No dependencies set.

Reference: starred/terminal#31865
Delete Branch "%!s()"

Deleting a branch is permanent. Although the deleted branch may continue to exist for a short time before it actually gets removed, it CANNOT be undone in most cases. Continue?