What I get from this pixiv entry is that it refers to characters who give impression of being well-raised in old-fashioned way with aloof and dignified aura surrounding them. In this context, Colorado gives off impression of being out-of-touch elitist young lady archetype due to her smug expression in her base CG.
In the other hand, they're also prone to being reduced to 'straight man' or even flustered mess/butt of the joke in situations they absolutely have no control over (as seen in her damaged CG ), dispelling whatever initial impression they gave to audience. I guess it's a type of gap moe? Though it can also double as mean insult since she's also part of old generation battleships.
Long story short, I think Munmu's take on Colorado describes this trait really well, lol.
From what I can see in the article, the term refers to characters who initially appear very composed, aloof and cool, but have some unexpected weakness, so at critical moments, they turn into epic natural airheads, become totally incompetent in combat, and/or just reach their wits' end so their speech and behavior fall apart in some manner. They can also be characters who are normally goofballs but are trying to act cool.