After the best-selling children’s books illustrator Loren Long finished a Facebook live art video in The Times studio, his publicist noticed a viewer comment from Mr. Long’s brother. “He says you’re colorblind,” she said, shocked. Mr. Long admitted it was true. He had never talked about his colorblindness publicly, he said.

As an admirer of Mr. Long’s beautiful — and colorful — picture books, like the Otis the tractor series, “Of Thee I Sing,” by Barack Obama, “Little Tree” and his newest book, “Love,” which will be published Jan. 9, I was shocked too. I asked him if he’d tell me more. These are edited excerpts from the conversation.

Why have you never revealed that you’re colorblind?

Early in my career I kept it secret because I was worried that it would hurt my ability to get hired. If an art director or editor knew I was colorblind, would they want to work with me? I also just didn’t want to call attention to myself, when people have overcome far greater odds than mine. I think of it as an “obstacle” as opposed to a “disability.”

How did you first discover it?

I was 14 and I’d started having a hard time seeing the chalk board at school. My mom took me to the optometrist. He found a little bit of nearsightedness. But he also gave me something I’ve now learned is called the Ishihara color test. As we were leaving he said, “By the way, Mrs. Long, did you know your son is colorblind?”