Although it could be GBR but not all blue rams are BGR. It could simple blue ram which I know is not as colorful nor strong as BGR. I think this one is more commonly and simply known as blue ram.
BGR is selectively bred morph of blue ram and was avail to our market on regular base for about 10-15 yrs. I know there are still common blue rams avail on the market and they are usually cheaper than GBR.
I could see the tucked in belly. I dont think it will go after any veggie at this point.
Try blackworm or other frozen insect larvae, provided water parameters are within acceptable range for Ram.