What do we mostly know Matisse for? Vibrant colours! He was a pioneer when it came to colour. Yet he was so much more. His style could be recognized by the pulsing feeling of the images. The composition itself with lines that mostly connect at odd angles. Another thing is that he used conplementary colours as shades, instead of using more neutral shading, such as browns, greys and blacks.
The coloring contributes to the feeling of an alternative reality, even though the motif itself is quite realistic, yet not really. The scene of people sitting in a park and enjoying themselves is a possible one. The concept of doing it while being nude is maybe harder to execute in real life, but hey, there are always secluded spots in nature. The painting therefore combines the element of the real human body, with the strange colouring and scenes.