But even I can see a red warning as you quoted above for the OP's started threads, don't know how a red warning is triggered even though it's a type 1 flag but it's wired.
It will show red for newbies and guests when they will click on the thread link only. Yellow warning showing when you clicked on the flag link I have created. Means red will visible to you when you logout and click thread link those have created by flagged user. (I have tried it by logout my account). The type 1 flag is also red. But I prefer and recommend that people call them "flag type 1/2/3" so we can all know what people are talking about.
Agree, rather than call red flag we might mention it as flag type 1 so it will quite easy to realize which flag has been raised. 
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