What's a 'Red-Letter Christian'?

[Friar_David_O.Carm]

Anima Christi:

I suspect the reason they call themselves “red-letter Christians” is because in some Bibles, especially protestant ones, the words of Jesus are printed in red letters, and liberals are fond of pointing out that “Jesus never spoke about homosexuality or abortion but He spoke about helping the poor a lot.” I won’t talk about the fallacy of that argument now but that is probably the reason they call themselves “red letter christians.”

That is exactly what I am getting at.

They seem to want to say that the message of Jesus is different than the message found in the rest of the Bible.

As if the red letters make them, somehow, more the Word of God than the rest of the Word of God.