HI

even I have a similar issue.

we can't upgrade Infragistics version. we are using angular 9  and some third party libraries so we can't immediately upgrade the angular version.

And we checked the css,

we are not using infragistics.theme.css, and we were commented igniteui-angular.css.

After we comment this charts colors are showing properly, but grid styles are gone because we commented the  igniteui-angular.css.

Below is the styles array in  angular.json

"styles": [
“node_modules/bootstrap/dist/css/bootstrap.min.css”,
“node_modules/font-awesome/css/font-awesome.css”,
“node_modules/ngx-ui-switch/ui-switch.component.css”,
//”node_modules/@infragistics/igniteui-angular/styles/igniteui-angular.css”,

“src/styles.css”
],

So the chart issue is in default css( igniteui-angular.css.) only.

Can you please check again and let me know If there is any solution. (or) please raise a ticket.

Let me know If you nee any other information.

Thanks