ラーオ語
The word "Lam" is spelled to the "Rung" (ຮຸ່ງ) in the Lao language what means "bright". Old Vietnamese idioms have the "Sông Rung rú Hống" (Rung river and Hong mountain) and "Sông Lam rọi núi Hồng" (Blue river lights up Red mountain).