That’s a cool historical fact but the modern colloquial usage is synonymous with poor (financially) countries.

A 'modern colloquial usage' that's mildly described as a 'stereotype' on Wikipedia. A more precise description is that it's a revisionist redefinition that represents the disdain towards countries that refused to sacrifice their sovereignty for money, after suffering extended periods of exploitation. And it predictably undermines the historical picture of the socioeconomic realities that existed during the cold war - a picture that doesn't resemble in any way what the US is inflicting upon itself now.