Marker Arrow formatting

?? re CSS formatting of the marker arrow at left of each title: How can this be edited?

I have the following in CSS to change the color of the arrow to gold while the title remains blue, which works in Firefox. However, does not work in Chrome or Safari. How to correct??

.ab-accordion-title::marker {
color: #e7ae4c;
margin-left: -20px;
}

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