In Keynote, the "stroke" option for text boxes includes "picture frame". It is possible to change the fill color, but I can find no way to change the frame color, such as is possible when using "line"; the "frame" isn't selectable. Hard to believe this isn't possible, but I can't find out how. Anybody know? (I'm not talking about work-arounds, which I can make when it's really necessary.)
Picture Frames cant be altered in Keynote. You will need to use your workaround method.