ElementColorProvider - Determining class of PSIElement or reference

I am adding color previews based on a custom framework we have.  I have the logic to determine the color working and the GutterIcons are applied correctly, but I am new the Intellij SDK and could use some guidance on how I can check if a PsiElement meets at least one of two criteria:

1. The element is the class or a derivative of a given type (for instance class Bar in Kotlin)

2. Is calling a variable that is the class or a derivative of a given type (for instance class Bar in Kotlin)

It is a lot like finding usages.

Thanks in advance!

internal class FooColorProvider : ElementColorProvider {

    override fun getColorFrom(element: PsiElement): Color? {
        if (element !is LeafPsiElement && element.firstChild != null) {
            return null
        }


        if (element.elementType.toString() != IDENTIFIER) {
            return null
        }


        //todo@patches - Figure out how to determine if this is a reference to the specified class or the specified class itself

        return getColorForElement(element)
    }

    override fun setColorTo(element: PsiElement, color: Color) {
        if (element !is LeafPsiElement && element.firstChild != null) {
            return
        }

        NavigationGutterIconBuilder.create(ColorIcon(GUTTER_ICON_SIZE, color))
            .setTarget(element)
    }

    /*
     * Private functions
     */

    private fun getColorForElement(element: PsiElement): Color? {
        // Omitted for brevity
        return null
    }
}