Highlight text variables frames in InDesign

Hi

i would like to run a script to highlight the text variables frame just so that when i am working in the file i can see what is a variable and share with the client on what variable text that have in the file.

I know i can do it as a character style as below, (i have used orange to highlight the variable tex) but i really want to just highlight the box that the varible is within. Note not the text frame itself the actual variable frame that indesign adds pctured inside the text frame below.

Please can anyone help with this