Vincent had the crab painted in red colour against a bright green background in the crab on its back painting. In this work, the artist decided to try with what is known as the 'laws of color,' as was illustrated by Eugene Delacroix, a French painter.
They can be boy described as complementary since they form a perfect pair and deliver an aggressive effect when positioned side by side. Van Gogh strongly admired Decalcroix and learned about the ideas of his colour theories from books written by Charles Blanc.
The crab on its back is one of the last drawings by Vincent Van Gogh before he passed on. But it is understood that this perfect work of art was created when there was not enough technology, so it was clearly a tough one. From one of his letters, Vincent pointed out that accuracy contributes to art and that without it, artists would find it hard to make their work stand out. Also, crabs are rarely on their backs, so it is hard to imagine how Vincent got the angles right without missing any detail.
The drawing has a clear background of sea green that serves as complementary to the colours of the crab's legs. The piece of art also features bold brushstrokes, which means it was done in a hurry. A keen observer would notice that the crab was drawn using a narrower round brush, which might explain why Vincent got all the angles right. The ends of the legs, however, seem to be drawn using a watercolour brush.
The crab on its back is one drawing with a lot of contrast going on and might take a lot of professionalism to interpret. For instance, the crab's front legs seem to be strong and voluminous, while the hind ones are small and rather fragile. The painting also has complementary colours that play off each other.
Vincent Van Gogh had quite a number of paintings, but some of them stood out than the rest, like the crab on its back. Crabs are animals with strong shells, and they are always upright. But here is one that is upside down, revealing its soft, vulnerable side.