Is it possible to access window components from the project library scripts?

[pturmel]

@nminchin

in a Vision Client Tag

Not necessary. A Vision Client Tag Change Event would suffice.

@rahman.tarek

a tag change event is calling

You don't. Or more precisely, not from gateway scope.

You write your script to run in some client scope, Vision or Perspective. See this related discussion:

Automatic Function

Aside from the style customizer, which is a Vision thing, the key to the question is to use an expression binding to translate your tag values into a range of colors or indices for colors. Whether Vision or Perspective. I highly recommend you bind the source tag to a custom property (perhaps indirectly), and then use that property in your expressions or styling. Note that one "pulls" the tag into the UI for evaluation--you don't "push" from the tag to the UI. That is, don't try to do this so…

Note especially how your UI should pull the data it needs from global resources, including tags, not have those resources try to push to the UI.