Is it possible to show full color icons for widgets

[daleasberry-n]

I've discovered that in index.css, the way to set the widget icon is as follows:

.my-icon-class {
-webkit-mask: url("../images/my.svg");
mask: url("../images/my.svg");
}
.another-icon-class {
background-image: url("../images/my.svg");
}

Using another-icon-class doesn't work. Is it possible for Theia to show the actual icon, rather than a mask over black or white (depending on the theme)?