Yeah, you can leave out いろ for most Japanese color words and it's equally correct. It's usually more common to leave it out most of the time.
むらさきいろ- purple color むらさき - purple
このぼうしはむらさきです。このぼうしはむらさきいろです。むらさきなぼうし。むらさきいろのぼうし。 You can use both
Why is "pink color" correct for ピンクいろ, but not "purple color" for むらさきいろ? It seems inconsistent.
いろ should not be used in either. Japanese people rarely say that, mostly under specific circumstances where they want to specify color.
Violet is STILL marked as wrong, after all this time. I have reported this so many times, kind of annoying at this point. shrug
Purple and violet are the same in Japanese, but they do not accept "violet". That has to be fixed.
What I find disturbing in this section is how Duolingo randomly chooses to teach some colors with kanji and some colors with hiragana/katakana.
Is this author related, or is her name just a homonym? https://www.goodreads.com/author/show/4739.Murasaki_Shikibu
"Orange" including "iro" I could kind of understand, but pink, purple, and green? Why?