What does 5 mean in Feng Shui?

The nine flying stars in residential feng shui are divided into one white, two black, three blue, four green, Huang Wu six white, seven red and eight white nine purple, among which five are auspicious stars and four are ominous stars.

I think it refers to Huang Wu and Saturn: this star is the fiercest of the nine planets, and it is dedicated to making trouble.