Cryptic coloration is the most common form of camouflage, found to some extent in the majority of species. The simplest way is for an animal to be of a colour similar to its surroundings.
The female Misumena vatiaspider switches her body colour over the course of days depending on the flower where she lurks. This is often cited as an example of cryptic coloration. However, according to a new paper in Proceedings of the Royal Society B, a white spider on a white flower doesn’t catch more prey than a white spider moved to a yellow flower. Nor does a yellow spider on a yellow flower get a colour-coordination bonus. The study may shatter the myth of crypsis by colour matching in crab spiders. For further details see http://www.sciencenews.org/view/generic/id/49079/title/Textbook_case_of_color-changing_spider_reopened