Many broadcasters have their own specifics. That broadcaster you're submitting to can give you their broadcast spec sheet. Every broadcaster has one.
Basically, video you should color grade to bring brights to no more than about 97 percent, and don't crush shadows very much.
The audio you don't want to go much beyond -6db, don't every peak over -4db. But, to comply with the CALMS Act (if you're in the US) is to use a LUFS meter. I favor one by Klangfreund, but there are others by Wave, a few others. The broadcaster's spec sheet should have a LUFS range they demand.
As someone who makes a living in broadcast, I can tell you that Broadcast Safe is still the same in digital as it was in analog. Highlights, overly saturated reds, all still affects the signal the same way, it is universal. Broadcast Specifications is a term, but it refers to the individual specs of delivered material each station has for itself (codecs, frame rates, etc).