It requires 8.1.19 or newer: system.perspective.alterDock - Ignition User Manual 8.1 - Ignition Documentation
If you're looking to modify the color of the icon, you'll need 8.1.22 or newer, and you'll need to setup your own css rule to "animate" the color swapping:
Starting with the 10/4/2022 Nightly (8.1.22) build, users will be able to modify a new styling resource: stylesheet.css
This new resource is considered an advanced feature and will not be in place by default. To place the resource, expand the Perspective node of the Project Browser, right-click the Styles node, and select "Enable Advanced Stylesheet".
[EnableStylesheet]
Once in place, the stylesheet allows for inserting CSS just as you would in any normal CSS file. The rules defined in this r…