This design reflects all the natural colors inspired from our Mother Earth. The aim of this is to evoke the feeling of staying grounded to our roots. Natural, household colors like Red, Green, Brown (spices), Yellow (Turmeric) add flavors to our lives. 
The blessing hand in Red symbolizes Love, passion and courage which Ganesh ji bestows upon us. Shades of Yellow, Orange stand for energy, happiness, and purity. Green symbolizes New beginnings, hope and rebirth which has a strong connection with Lord Ganesha (the reason why we worship the Lord before starting anything new)
This Ganesh chaturthi, may Lord enlighten all homes with happiness, good health and fortune. 
Happy Ganesh chaturthi!!!