How to style the scrollbars of the Angular MultiSelect?

[Christopher]

How can I identify the primary scrollbars of the MultiSelect control to be able to modify their appearance?

I have tried to highlight the scrollbar-button so see if I am on the right track with each of these, one-at-a-time:

• .kc-input-base::-webkit-scrollbar-button:single-button
• .kc-input-base ::-webkit-scrollbar-button:single-button
• .kc-input-base > ::-webkit-scrollbar-button:single-button
• .kc-input-base > ::ng-deep::-webkit-scrollbar-button:single-button
• .kc-input-base > ::ng-deep.k-multiselect-wrap::-webkit-scrollbar-button:single-button
• .kc-input-base > ::ng-deep.k-multiselect-wrap ::-webkit-scrollbar-button:single-button
• ::ng-deep::-webkit-scrollbar-button:single-button

The multiselect is defined as:

        <kendo-label class="k-form k-form-label" text="Coverage">
          <kendo-multiselect
            [data]="coverageCodes"
            formControlName="coverageCode"
            [autoClose]="false"
            [textField]="'name'"
            [valueField]="'key'"
            class="input-search-flex kc-input-base"
            (valueChange)="valueChange($event)"
            [clearButton]="false"
            DropDownFillMode="outline"
            [popupSettings]="{ popupClass: 'kc-popup' }"
          >
          </kendo-multiselect>
        </kendo-label>

This is the result:

 

As you can see, the scrollbars never changed color.