Old term for Mandarin that is heavily influenced by a local dialect, or spoken with a thick provincial accent. The phrase uses "blue-green" as a metaphor for something that is unrefined or not pure in color.

To talk officiously or use official jargon; to make empty promises or use high-sounding language to evade responsibility or deal with people superficially.

a group of Mandarin Chinese dialects spoken in parts of Jiangsu and Anhui provinces

Southwestern Mandarin, a dialect group of Mandarin spoken primarily in southwestern China

the Amharic language