Accessibility - High contrast theme on activity bar inconsistent

[RedyAu]

Type: Bug

1. Enable any high contrast theme

2. Hover over the activity bar icons
   Normal:
   
   Some extensions (no dashed outline):
   

3. Click activity bar icons
   Normal:
   
   Some extensions (no outline):
   

Expected:
All icons behave the same

Actual:
Icons available by default are consistent, but other icons' look varies depending on Extension support.

Solution:
This issue doesn't feel like it should depend on Extension support. Understandably not many Extension developers use High-Contrast themes, so lack of support is easy to miss. This should probably be fixed upstream, so that Activity Bar icons can only behave in one way.

VS Code version: Code 1.98.2 (ddc367e, 2025-03-12T13:32:45.399Z)
OS version: Windows_NT x64 10.0.22631
Modes:

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-9750H CPU @ 2.60GHz (12 x 2592)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled webnn: disabled_off
Load (avg)	undefined
Memory (System)	23.90GB (5.99GB free)
Process Argv	--folder-uri file:///c%3A/GitHub/lyric --crash-reporter-id ee03a05e-9a6e-4778-8b8a-c72b2ec19706
Screen Reader	no
VM	0%

Extensions (94)

Extension	Author (truncated)	Version
adb-qr	Aak	0.2.0
better-comments	aar	3.0.2
vscode-icalendar	af4	1.0.1
vscode-nginx-conf	ahm	0.3.5
Bookmarks	ale	13.5.0
vscode-sqlite	ale	0.14.1
a-file-icon-vscode	ato	2.0.1
vscode-intelephense-client	bme	1.14.3
vscode-tailwindcss	bra	0.14.12
exe-runner	bra	1.1.1
vscode-opennewinstance	chr	0.0.15
npm-intellisense	chr	1.4.5
path-intellisense	chr	2.10.0
vscode-express	Com	0.0.5
dart-code	Dar	3.106.0
flutter	Dar	3.106.0
mustache	daw	1.1.1
vscode-eslint	dba	3.0.10
es7-react-js-snippets	dsz	4.4.3
gitlens	eam	16.3.2
vscode-html-css	ecm	2.0.13
vscode-flutter-i18n-json	ess	0.28.0
vscode-gift	eth	0.1.11
vscode-gift-pack	eth	0.0.3
vscode-gift-preview	eth	0.0.15
font-switcher	eva	4.1.0
vscode-diff	fab	2.1.2
html-preview-vscode	geo	0.2.5
copilot	Git	1.293.0
copilot-chat	Git	0.25.1
remotehub	Git	0.64.0
vscode-github-actions	git	0.27.1
vscode-pull-request-github	Git	0.106.0
gc-excelviewer	Gra	4.2.63
vscode-graphql	Gra	0.13.2
vscode-graphql-syntax	Gra	1.3.8
todo-tree	Gru	0.0.226
rest-client	hum	0.25.1
discord-vscode	icr	5.8.0
better-cpp-syntax	jef	1.27.1
vscode-peacock	joh	4.2.2
vsc-python-indent	Kev	1.21.0
google-apps-script	lab	0.2.2
flutter-intl	loc	1.19.3
dart-import	lua	0.3.1
vscode-moodle-snippets	Mat	1.0.346
vscode-pdf	mat	0.1.5
asm-code-lens	maz	2.6.2
rainbow-csv	mec	3.18.0
syntax-mcfunction	Min	1.0.1
vscode-docker	ms-	1.29.4
csharp	ms-	2.69.25
vscode-dotnet-runtime	ms-	2.3.0
debugpy	ms-	2025.4.1
isort	ms-	2023.10.1
python	ms-	2025.0.0
jupyter	ms-	2024.11.0
jupyter-keymap	ms-	1.1.2
jupyter-renderers	ms-	1.1.0
vscode-jupyter-cell-tags	ms-	0.1.9
vscode-jupyter-slideshow	ms-	0.1.6
remote-containers	ms-	0.401.0
remote-ssh	ms-	0.118.0
remote-ssh-edit	ms-	0.87.0
remote-wsl	ms-	0.88.5
azure-repos	ms-	0.40.0
cpptools	ms-	1.23.6
hexeditor	ms-	1.11.1
live-server	ms-	0.4.15
remote-explorer	ms-	0.4.3
remote-repositories	ms-	0.42.0
vscode-serial-monitor	ms-	0.13.1
vsliveshare	ms-	1.0.5948
vscode-flutter-freezed-helper	mth	0.1.0
gremlins	nho	0.26.0
indent-rainbow	ode	8.3.1
material-icon-theme	PKi	5.19.0
vscode-xml	red	0.28.0
flutter-riverpod-snippets	rob	1.2.2
ssh-here	sat	0.0.3
markdown-preview-enhanced	shd	0.8.15
mcscript	Ste	0.0.3
even-better-toml	tam	0.21.2
lilypond	tru	0.0.1
errorlens	use	3.23.0
vscode-svg-previewer	vit	0.7.0
vscode-nginx	wil	0.7.2
php-debug	xde	1.35.0
php-pack	xde	1.0.3
txt-syntax	xsh	0.2.4
pretty-ts-errors	Yoa	0.6.1
save-as-root	yy0	1.10.0
markdown-all-in-one	yzh	3.6.3
php-intellisense	zob	1.3.3

(5 theme extensions excluded)

A/B Experiments

vsliv368cf:30146710
vspor879:30202332
vspor708:30202333
vspor363:30204092
vscod805:30301674
binariesv615:30325510
py29gd2263:31024239
c4g48928:30535728
azure-dev_surveyonecf:30548226
962ge761:30959799
h48ei257:31000450
pythontbext0:30879054
cppperfnew:31000557
dwnewjupyter:31046869
nativerepl1:31139838
pythonrstrctxt:31112756
nativeloc1:31192215
iacca1:31171482
5fd0e150:31155592
dwcopilot:31170013
6074i472:31201624
dwoutputs:31242946
customenabled:31248079
hdaa2157:31222309
copilot_t_ci:31222730
850i5325:31264362
968h8231:31271074
jda6j935:31233686
pythoneinst12cf:31262606
bgtreat:31268568
fh1c7952:31258891
4gafe986:31271826
31787653:31262186
3e8i5726:31271747
49da9784:31264548

[RedyAu]

Related: #143533 #146421

[Sokjomblo]

me wan to advicer