Trying to learn,
Actually you get it done with just the text dashboard node as long as your flow manages to deliver the correct data (color) inside msg.payload, like on below flow (just an example).
[{"id":"7a9e12d2.b175cc","type":"tab","label":"Flow 3","disabled":false,"info":""},{"id":"99d34e2e.c8784","type":"inject","z":"7a9e12d2.b175cc","name":"","topic":"","payload":"lime","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":"","x":221,"y":268,"wires":[["63b99929.c57038"]]},{"id":"63b99929.c57038","type":"ui_text","z":"7a9e12d2.b175cc","group":"5a51405f.04d11","order":3,"width":"3","height":"1","name":"","label":"LED","format":"<font color={{msg.payload}} ><i class=\"fa fa-circle\" style=\"font-size:24px;\"></i></font>","layout":"row-left","x":416.00000762939453,"y":286.00000381469727,"wires":[]},{"id":"3c166ca0.189214","type":"inject","z":"7a9e12d2.b175cc","name":"","topic":"","payload":"red","payloadType":"str","repeat":"","crontab":"","once":false,"onceDelay":"","x":221,"y":308,"wires":[["63b99929.c57038"]]},{"id":"5a51405f.04d11","type":"ui_group","z":"","name":"LED Testing","tab":"d2de201f.cc973","disp":true,"width":"4"},{"id":"d2de201f.cc973","type":"ui_tab","name":"Tab","icon":"dashboard","order":0}]