erminal text becomes unreadable in light themes due to black background rendering

Type: Bug

Description

When using a light theme in VS Code, terminal output sometimes renders with a black background while the text remains dark, making the content nearly impossible to read.

Steps to Reproduce
Switch VS Code to a light theme (observed with multiple light themes).
Open the integrated terminal.
Run a command such as:
Shell
1
npm run dev
Show more lines
Observe the command text in the terminal.
Expected Behavior

Terminal text should remain clearly readable and maintain sufficient contrast with the background regardless of the selected light theme.

Actual Behavior

Parts of the terminal command are rendered with a black background while the text remains dark, resulting in very poor contrast and making the command difficult or impossible to read.

Additional Information
The issue appears to affect most light themes.
The problem is visible in the integrated terminal.
In the screenshot, the text run dev is displayed on a black background, causing a readability issue.
This seems to be a theme/terminal color contrast regression or incorrect ANSI color rendering.

VS Code version: Code 1.133.0 (a5b500951314efd502d07465bd138dfbd714a960, 2026-08-11T22:14:08Z)
OS version: Windows_NT x64 10.0.19044
Modes:

System Info

|Item|Value|
|---|---|
|CPUs|Intel(R) Xeon(R) Gold 6258R CPU @ 2.70GHz (8 x 2700)|
|GPU Status|2d_canvas: unavailable_software
GPU0: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VENDOR=Microsoft, DRIVER_VERSION=10.0.19041.4355
GPU1: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.19041.4355
GPU2: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.19041.4355 *ACTIVE*
GPU3: VENDOR= 0x1414, DEVICE=0x008c [Microsoft Basic Render Driver], DRIVER_VERSION=10.0.19041.4355
Machine model name:
Machine model version:
direct_rendering_display_compositor: disabled_off_ok
gpu_compositing: disabled_software
multiple_raster_threads: enabled_on
opengl: disabled_off
rasterization: disabled_software
raw_draw: disabled_off_ok
skia_graphite: disabled_off
trees_in_viz: disabled_off
video_decode: disabled_software
video_encode: disabled_software
webgl: unavailable_software
webgpu: unavailable_software
webnn: unavailable_software|
|Load (avg)|undefined|
|Memory (System)|32.00GB (10.60GB free)|
|Process Argv|--crash-reporter-id b1e5d0e0-bcd0-4c81-a1c2-45c19910b231|
|Screen Reader|no|
|VM|100%|
Extensions (6)

Name|Identifier|Author|Version
---|---|---|---
Prettier - Code formatter|esbenp.prettier-vscode|esbenp|12.4.0
C# Dev Kit|ms-dotnettools.csdevkit|ms-dotnettools|3.20.199
C#|ms-dotnettools.csharp|ms-dotnettools|2.140.9
.NET Install Tool|ms-dotnettools.vscode-dotnet-runtime|ms-dotnettools|3.1.0
Ayu|teabyii.ayu|teabyii|1.1.12
Vue (Official)|vue.volar|Vue|3.3.9

A/B Experiments

```
vsliv368:30146709
binariesv615:30325510
nativeloc1:31344060
dwcopilot:31170013
dwoutputs:31242946
copilot_t_ci:31333650
e5gg6876:31282496
pythonrdcb7:31342333
6518g693:31463988
aj953862:31281341
envsactivate1:31551504
cloudbuttont:31379625
3efgi100_wstrepl:31403338
56b7f661:31457055
ec5jj548:31422691
cmp-cht-control-diffpatch-2in1-lysithea-0014-comp-2:31560621
cp_cls_t_966_ss:31526232
4je02754:31466945
c3h7c220:31478652
ge8j1254_inline_auto_hint_haiku:31490510
cp_cls_t_1081:31454832
conptydll_true:31498968
core-renderer-profiling-on:31440367
e9c30283:31461165
test_control1:31471004
c9b86496:31447327
ei9d7968:31496641
nes-extended-on:31455476
chat:31457767
8hig5102:31480529
89g7j272:31518289
i2gc6536:31499202
52612955:31516516
ghj88844:31499326
ec1eg703:31520046
ddid_c:31478207
hmra_i5g22:31518061
7df3h592:31512476
cp_cls_t_1082:31535311
logging_enabled_new:31498466
db5d2638:31499441
jb_cp_cls_t_632:31543129
56dj4588:31512888
32d76977:31512328
ha629193:31508444
cdk-lw-on:31524445
jh5f2457_c:31540921
jbcp_cls_pctr_t:31531130
61138546:31518536
cp_intellij_t_nes:31548657
gf14b233:31526830
ahp-both-windows:31556933
sessions_5:31532894
ihg5j128:31534457
f412h606:31551416
9gg7f176:31542112
enable_editor_pane_layout:31566296
allow-none:31555437
fd5dc207:31551400
36h42362:31564511
c7c27ce7:31554789
1h923230:31564177
1532g621_copy:31554320
treatment-23-1:31555779
unuse_dynamic_mcp:31555281
switchtoauto:31559321
0c1h4866:31566224
vrbsty_fls:31561059
session-archive:31558132
5b8j3302:31564601

```