Powerline symbols in the terminal get wrong colors

[oleq]

Does this issue occur when all extensions are disabled?: Yes

• VS Code Version: Version: 1.66.0
• OS Version: macOS Monterey 12.3 (21E230)

Steps to Reproduce:

1. Use a powerline-friendly prompt with fancy triangles (\ue0b0) in the terminal.
2. Open the terminal.

Expected

How this should look (before 1.66.0)

Actual

The triangles got some mixed colors.

Info

• The prompt works correctly in iTerm, Terminal, etc. (so this is VSCode),
• This fails in all shells in VSCode: bash, zsh, or fish.
• This fails with or without customizations to workbench.colorCustomizations like terminal.ansi*.

[yume-chan]

"terminal.integrated.minimumContrastRatio": 1

[oleq]

"terminal.integrated.minimumContrastRatio": 1

Works like a charm, thanks. This could be mentioned in https://code.visualstudio.com/api/references/theme-color, though.

[rewrking]

"terminal.integrated.minimumContrastRatio": 1

Thanks. Would love to know why this isn't the default.

[oleq]

"terminal.integrated.minimumContrastRatio": 1

Thanks. Would love to know why this isn't the default.

WCAG accessibility guidelines. To make colorful terminal applications look at least okayish no matter the user theme. Makes sense. Mentioned in https://code.visualstudio.com/updates/v1_41#_minimum-contrast-ratio.

I wonder why this affected my setup now since this has been implemented since 1.41 in 2019? What changed in the recent 1.66 update? 🤔

[yume-chan]

Yes, it was changed in this month #144762 (comment)

[rewrking]

WCAG accessibility guidelines. To make colorful terminal applications look at least okayish no matter the user theme. Makes sense. Mentioned in https://code.visualstudio.com/updates/v1_41#_minimum-contrast-ratio.

Yeah, but IMO 4.5 shouldn't be the default because suddenly the ansi terminal colors requested aren't the ones requested. It's another layer of confusion on top of something already confusing. This change isn't really a net benefit.

[levrik]

I'm also confused why it changes the color of the powerline rectangles? This doesn't seem to be correct or am I missing something here?

Edit: Ah. Probably because the background is used to fill the rest of the character with the following color, I see.

[jaminthorns]

My prompt uses Powerline symbols, so I had this issue after upgrading to 1.66 as well. I think making the terminal accessible by default is a good call, but it also presents a problem for prompts that switch between using the same color for background and foreground to create the illusion of shaped blocks (like Powerline). I'm sure this affects heavily-customized vim and Emacs setups that do similar things, too.

If a user still wanted to have the contrast ratio functionality, it might be nice to have a setting like terminal.integrated.excludeContrastRatioAdjustment that would be a string of characters to exclude from contrast ratio adjustment.

[Tyriar]

This feature has been around for a long time but we changed the default in 1.66 as we're trying to make VS Code the most accessible code editor out there. You can see some of the background on the change here: #144411, I know this might cause an inconvenience but the net benefit is quite large:

• Themes/shells with incompatible colors (Solarized Dark Theme makes certain command line arguments invisible in PowerShell #144411) will no longer be invisible or super low contrast
• The terminal should be accessible regardless of your shell and operating system - accessibility is very important to our team
• It's trivial to disable by setting "terminal.integrated.minimumContrastRatio": 1, you could argue that it's hard to discover this but it's equally hard for users where this makes the terminal unusable to discover it for the inverse problem.

FYI @isidorn about feedback

Works like a charm, thanks. This could be mentioned in https://code.visualstudio.com/api/references/theme-color, though.

@oleq good idea!

I'm also confused why it changes the color of the powerline rectangles? This doesn't seem to be correct or am I missing something here?

@levrik yes it's because how powerlines works is a bit of a hack; for the triangle character, it inverts the background/foreground color so the shape on the left is the foreground and the negative space on the right is the background.

If a user still wanted to have the contrast ratio functionality, it might be nice to have a setting like terminal.integrated.excludeContrastRatioAdjustment that would be a string of characters to exclude from contrast ratio adjustment.

@jaminthorns I like the idea of excluding at the least the triangle powerline char from minimum contrast ratio 👍, this character will almost always be used to simulate the background color so it's a nice compromise. This also comes with the nice benefit of still retaining min contrast ratio in the prompt when a powerline is used.