How to make the light theme the default for my users?

We currently only implemented the light theme for our webviews in Theia, but the default theme is dark. We’d like to change the default until we have a chance to properly style the dark theme. Currently, we recommend our users to manually switch to the light theme the first time they login for a better experience.

An advice on what contribution point I could use to change the default theme would be appreciated.


[original thread by Dominique Rochefort]


try to add this section in your browser app package.json

  "theia": {
    "frontend": {
      "config": {
        "defaultTheme": "light"

[Dominique Rochefort]

Works like a charm! Thanks so much.

I tried doing it like this, but it doesn’t work :confused: I want a custom made theme as my default theme. When I change the entry to light it is still displayed in dark.

now, it should be workbench.colorTheme preference

How can I set this? It is not in package.json anymore, right?

@artem I believe we still use the defaultTheme prop in the package.json which is then used to set the workbench.colorTheme. I believe however that there may be regressions setting the theme with as I am unable to set a default theme as of yet.

How can I set this? It is not in package.json anymore, right?

@paulf98 for future reference, the default value of preferences can also be set in your custom application’s package.json as such:

So in my case none of these two opportunities seem to work :confused:

@paulf98 if you are experiencing issues (on master), please feel free to open an issue on the main repository so we can track the regression and provide a fix :+1: