With .CO, I think it's main selling point (outside Colombia) is brevity.
So I think single-word .CO's are best.
And words that define a company's primary product.
The only item that meets those criteria (which are just my own criteria) would be Videotapes.co.
However, videotapes are an outdated technology; so I'm not sure how many companies would want to name themselves after videotapes. Some companies do work with archival video tapes, that's true. So maybe they'll be interested.
If "Plage" were Spanish for beach, then you'd have something of value. But I only see .CO selling for English and Spanish.
The gold domains aim for a lucrative niche; but, again, they're 2-word domains and maybe not the right type to name a business.