If your camera does offer an RGB historgram, use it. Here’s why:
If you rely on a standard histogram to determine whether or not you’ve blown your highlights or lost detail in your shadows, then you’re only getting about one third of the information you need to make an accurate decision.
Most modern cameras offer a regular histogram mode by default that merely represents the green channel. Unfortunately, this is the channel least likely to show clipping. If you have the ability to turn on an RGB histogram, you get to see the red and blue channels as well. Without this information, you may be losing detail and not know it if you’re only viewing the single histogram. That’s why it’s a best practice to set your camera up so it defaults to an RGB histogram if it’s available.