OK, the lady is obviously curvy and feminine, yada yada. She has her hand over her belly, lovingly and protectively.
The blue stripe at the bottom is water, which represents the fluidity and natural flow of this woman. She also has a bubble of water in her, so it shows her connectedness to the earth in this stage. Without water, there is no life, so the water sustains her and she is also baring new life with water within.
The green stripe is grass/vegetation. And the baby inside her is a little green sprout like a seedling. Echoing the same sentiments as the water. It sustains her and she is contributing back to this lifeforce by creating new life.
The yellow stripe is the radiance of the sun, and the woman is also radiating and glowing. Almost like deity. There are people (who look really stupid, which isn't significant ok? ;))of all ages and sizes etc looking on at her and smiling. She is doing humanity a service by creating new life and humanity admires her. She is important, in the forefront, the only one with detain and curves etc. This is her moment to shine and be really special.