浓 → ☊ nong2 
concentrated; dense; strong (smell etc) ☊ 
Tập trung ☊ 浓缩 ☊ → 提浓 ☊ → ☊ → 
concentrate 集中 ☊ → 专注 ☊ → 浓缩 ☊ → concentration (色彩的)浓淡 ☊ → 深浅 ☊ → ☊ → shade 厚的 ☊ → 浓的 ☊ → ☊ → thick