我没有Android的工作室自己。然而，在颜色preVIEW红UnknownType来看，你所寻求的颜色是不是未解决的符号，而是一般的错误。寻找错误或类似的东西就行了。您也可以尝试点击UnknownType，在颜色preVIEW，也许Android的工作室是足够聪明，从列表中选择的颜色适合你。

I don't have Android Studio myself. However, judging by red "UnknownType" in colors preview, the color you seek is not "unresolved symbol", but instead generic error. Look for "Error" or something like that on the list. You can also try to click "UnknownType" in colors preview, maybe Android Studio is smart enough to select the color from the list for you.