Ivan Ivarson's paintings are never direct representations; rather, they are filled with his warm feelings for nature. The painting is expressive and often intensely vibrating in its colouristic strength. He paints the sky, the sea, the earth, the woman, and the child—elements that for Ivarson represented the dream of nature's joyful splendours. Professor Torgny Segerstedt, also the chief editor of Göteborgs Handels- och Sjöfartstidning, supported Ivarson, and thanks to him, Ivarson had the opportunity to undertake study trips during the late 1920s. The trips took him to Italy and France, which were important years for Ivan Ivarson as he developed his painting in a more resonant colouristic direction.

Ivarson was an incredibly hard-working artist, perhaps the most methodical and meticulous of the so-called Gothenburg colourists in reworking and reassessing his art. Ivarson provided few insights into his art and his working methods, but it is clear that he constantly altered his paintings. The ongoing working process and the painterly ambition result in a strong expressionist painting that differs drastically from that of his Valand colleagues and Swedish 1930s art in general. Ivarson possessed a truly unique painterly sensibility. His canvases are outward-looking and demanding in their approach. A telling quote from Arne Stubelius, Ivarson's mentor, often mentioned is;
"Yes, now it may be beautiful, but that is not what it should be. Now I will mess it up a bit. It has to go down first – all the way down to hell – before it comes up again. Otherwise, it won't hold up."