Hi Daniel Jung ,
I am not sure why you are doing it this way , but instead of this you could have created a field "Good" and "Bad" and drag that field to color in marks .Once you are done doing that
You can see ,you can change the color from that color card (Activity card ),over there click on drop down and you will get edit color.
And from here you can change the color.
Try doing this way ,and if i misunderstood something please attach the twbx file.