It is NOT possible !
You can not turn orange into "green" unless you are subtracting colors and then adding. A true green will can not be achieved but you could try getting a different hue of green. Try starting off with a small amount of orange and drawing out the red by overwhelming it with yellow. This will essentially give you a light orange. Try your best to get it as yellow as possible. Then add small amounts of blue to it until you've achieved a "green" that you are satisfied with.
No "color" can be added to orange to make green. HOWEVER, you can try to revert orange back to yellow by adding yellow to it until it's as yellow as possible. You'll more than liking end up with a very light orange. Gradually add small amounts of blue until you've acquired the green you desire. Side note: If you already have yellow in hand. There is no need for the orange. Just add blue to yellow!
Hemoglobin molecules liberated from red blood cells are broken down into subunits of heme, an iron containing portion, and globin, a protein. The heme further decomposes into iron and a greenish pigment called biliverdin. Biliverdin eventually is converted to an orange pigment called bilirubin.
Red and Yellow make Orange. Blue and Yellow make Green. Therefore, I would say that you need to dilute the orange with more yellow to get back as close to yellow as possible, then add blue.
Mixing opposite colors, like blue and orange, will create a colorful "black" which you can add white to create a grey color that will have a blue tint. Different mediums create slightly different colors. Some mediums like watercolor have a pigment called Payne's Grey, mix in an equal amount of any blue pigment and add water to lighten the color. If you use other mediums, like acrylic, you can mix black with white and add a blue pigment (it takes a lot of white to create a medium grey color). Or use the first method to create your own "black" and add white.
It is NOT possible !
pigment
the yellow pigment is called: xanthophyll the orange pigment is called: carotenoid
orange
the orange-yellow pigment in bile.
The color of Bilirubin is orange Bilirubin is an orange color pigment in the bile
yellow-orange
Purple and Orange
a soft orange
The pigment is known as carotene, which is an orange photosynthetic pigment, which just means it is a pigment found in chloroplasts responsible for catching light energy used in photosynthesis.
Start with a quantity of yellow pigment and mix in very small amounts at a time of red pigment until it looks like reddish-orange to you.
biliverdin