Support customizing the color of the flamegraph

[connor4312]

We got some feedback that users wanted to better match the flamegraph coloring to their theme. I tried some scheme to automatically pick an existing color from the theme, but didn't have good results. I think in part because we don't have a singular "flame"-like color, for example I tried using the border color of input validation errors, but on some themes this didn't work very well.

Kai suggested adding a new color for this that themes should customize. I'm not sure what it should be named, maybe just a "vibrant" color?

[miguelsolorio]

Since we are introducing webviews in custom views, I'd imagine we'll be getting a lot more data visualization extensions so having a set of chart accent colors would work in both scenarios. Thinking of something like chart.accentOne or chart.accentBlue like the terminal colors?

[connor4312]

Yea, that'd be good -- I can use that for the sidebar visualizer, where I'll have multiple lots, as well #755

[RandomFractals]

not sure what you are proposing here: that those settings become standard vscode theme styles?

Probably would not cover or be useful for a vast number of data viz extensions. maybe some simple use cases only.

There is much more than a primary color for a graph that goes into it. I don't know if chart prefix is a good idea either.

Do try some Vega viewer examples & see that if you want to go there, you probably want to add more than just chart.accentOne. What about ticks, grid lines, etc?

[RandomFractals]

you probably want to look at this repo for a comprehensive list of styles you'll need to make charts themeable: https://github.com/vega/vega-themes

[miguelsolorio]

@RandomFractals thanks for the heads up about how themes work in Vega. Our goal here is to start to create a baseline of chart colors that extensions can reference in webviews. We can't possibly create a token for every color that exists but the thought is we can start with primary colors and then if needed we can shift the hue of these colors if we need additional colors. Thanks to your feedback, we're also considering foreground and grid lines as well.

[connor4312]

Adopted the colors in microsoft/vscode-js-profile-visualizer@5d8e5eb and microsoft/vscode-js-profile-visualizer@485c3bd