The reference to “blue” refers to the bluish tinge in the black fur. You get that in the shade because light in the shade is bluish. The “yellow” refers to the burnt grass and the yellow eyes: a nice contrast to the blue light in the shade.
The cat is Charlie. He lives with me. He is a three legged black cat. He is a good boy cat. He likes staying at home, inside. I put him out on the grass so he could smell the air and be in nature for a while. He stayed for about 30 minutes and enjoyed it. He rolled over and talked to me.
He is now back on my bed, snoozing. The photograph is pretty well exactly as taken. There has been almost no Photoshopping. I just adjusted the contrast and colour saturation slightly.
You can see flecks of grey hair on his shoulders. He is not young anymore.