Transparent Quinacridone Magenta and Thalo Green was the most obvious
opposition.
It appears in both the high colors separately and in the shadows mixed.
Opaque Cadmium Red Medium in the flower and Transparent
Thalo Cyan were also present as high colors and shadow mixed darks.
Opaque Cadmium Orange and Opaque Cobalt Blue.
Yellow Green and Ultramarine Violet were the two prevalent oppositions.
Look at the perfect gray these two oppositions mixed to.
Dark Yellow Green is Synthetic Sap Green to Raw Umber, it's opposite is Ultramarine Violet.
All oppositions mix to a neutral gray.
Go to an active Real Color Wheel with all tube color oppositions clickable.