src/vs/editor/contrib/inlayHints/browser/inlayHintsController.ts/InlayHintsController/_fillInColors
class InlayHintsController:	private _fillInColors(props: CssProperties, hint: languages.InlayHint): void {
		if (hint.kind === languages.InlayHintKind.Parameter) {
			props.backgroundColor = themeColorFromId(colors.editorInlayHintParameterBackground);
			props.color = themeColorFromId(colors.editorInlayHintParameterForeground);
		} else if (hint.kind === languages.InlayHintKind.Type) {
			props.backgroundColor = themeColorFromId(colors.editorInlayHintTypeBackground);
			props.color = themeColorFromId(colors.editorInlayHintTypeForeground);
		} else {
			props.backgroundColor = themeColorFromId(colors.editorInlayHintBackground);
			props.color = themeColorFromId(colors.editorInlayHintForeground);
		}
	}