How to change colour scheme in an item view or board view which I created according to the theme selected by the user, is there any automatic API available like JIRA?

example: if I have used dark colour text in my App then in dark mode in doesn’t look good. I want to change my colours according to the theme selected. and if there is an API available it will be good!

You can use this to get the theme as part of the “context” object.

you can listen to for changes to context here, and update accordingly.

doing this I can listen to the change in theme but how do I change colour scheme to match the scheme of Monday, is there any colour palette one can follow!

Your code would control changing the theme, as well as choosing colors for use with the theme. However, there is some guidance in the style guide but you may need to capture colors from the UI to be precise.

is [monday-ui-style], an official repo, can I use it to change color scheme according to the themes?, if yes, how?

Yes it is in the mondaycom github workspace so it is official. It is SCSS, so I would presume you would use it accordingly.