Each shade of yellow determines it's meaning.
Yellow is full of creative and intellectual energy. It also deals with identity.
The solar plexus is the center of friendship, personal power, energy and self control, emotional issues and self acceptance. This chakra physically influences muscles, stomach, digestion, pancreas, liver, gallbladder, metabolism and the nervous system.
If this center is blocked you start lacking self esteem, and natural self love. Chances are you are not able to properly focus in business matters or personal matters. You may also find yourself not being able to fulfill your duties or even make right choices.
When the third chakra is balanced it brings the capacity to accomplish that which we want and allows us to relax and enjoy these accomplishments. We are able to successfully wield our own power and will which attracts prosperity and balance.
So if you are frustrated and feel that there are just too many demands on you Put some cheery yellow in your life and unblock theses wonderful energies.