Translation:I wear a blue shirt.
Because 青 means blue in this context (I guess it means blue in Japanese in most cases).
This word is the most confusing character expressing a color. In Chinese it can mean blue, green and black and usually confuses me a lot, so I avoid using it (in Chinese) except where the context limits its meaning sufficiently.
The translation literally said both blue and green were acceptable translations....
See sweg's comment. Basically "ao" doesnt cleanly match up with blue and includes some greens. In general its safe to use "midori" whenever you mean specifically green but there are two major exceptions -- both green traffic lights and vegetables are described as aoi, not midori.
When I learnt about the green and blue concept in Japanese, my reaction was exactly as in your profile picture...
みお ちゃん、これ は へん ですね？
More specifically, 蓝(lán) is blue, 緑(lǜ) is green, and 青(qīng) could be blue, green or black, depending on the object described and context. 青 is the more historic/literary word from back before Indo-European influences, when the line between blue and green was less concrete.
so... let's just say it's a kinda "dark cold colour". or perhaps even not necessarily dark?
青菜 and 青蛙 are green, 青天 and 《青鸟》 (an opera) are blue, 青丝 is black. And I (as a Chinese) don't know what 青色 exactly is....I avoid using it except some well-known contexts.
I'm guessing "I wear the blue shirt" would also be acceptable here? Duo doesn't currently like it.
One is a noun. The other is an adjective. There is a bit of over-lap (you can use 青 as a の adjective), but that is the main difference.
"Blue is my favorite color."
"I am wearing a blue dress."
"The sky is blue."
Forever getting the English word hunt wrong, instantly understand the sentence but I missed an "a" since my speed reading assumed it said "shirts" instead of shirt :/
Yes it would work. Japanese uses a lot of implying. So without 私は it would imply you're wearing the shirt. If you want to emphasize that you are wearing a blue shirt, add it. I found that in some places such as Japanese language classes, they like you to add 私は even though in everyday conversation you would usually omit it.