Newbie GUI: display a scalar output Value in GUI msg box???

Hi experts, so I am working in Simulink with flow charts. One of my flow charts give a certain scalar value at it's output port. let say a frequency value. depending on the input and certain limitation this values switches between 2.4 Ghz and 2.5 Ghz. I want these values to be shown in a GUI msg box. e.g for 2.4 one box becomes green and if value is 2.5 the 2nd box becomes green. Something like this. I hope It is clear what i mean if not I may explain it more in detail.

Regards Ali