1. Red: It symbolizes China's great ambition and firm belief in leading Youyu people to afforest barren hills.
2. Yellow: represents the spirit of Youyu people who never give up in the process of hard struggle and fighting against sandstorms.
3. Green: It symbolizes the vitality and hope of Youyu County to increase the forest coverage rate from 0.3% to 56% through unremitting efforts.
4. Blue: It represents the spirit of Youyu people who are full of hope and confidence in the future in the process of improving the ecological environment and pursuing a better future.
Therefore, the reason why the green monument in Youyu County adopts four colors is to symbolize the firm belief, indomitable fighting spirit and the future full of hope and confidence of Youyu people in the great cause of greening barren hills and improving ecology under the leadership of China.