Abstract Expressionism and Minimalism were the movement with the 20th century in the America and Europe.
Abstract Expressionism, during mid 20th century in America (left), was more into the state of mind and psychological. Their artworks were showing individual expression. And for Minimalism (right), they focused on the simple shape and form of paintings and sculpture, mainly in American during 1960s onwards.
The artwork from Mark Rothko, No.4, is similar to Black Square with Blue from Ellsworth Kelly when we look at the use of simple shapes and colours on the canvas, they could be the design of furniture and fashion. Also, we would need to spend time to look at the paintings and the emotions or feelings were given to the audience.
However, in my perspective, No.4 usage of colours are more blending to each other, except for the black colour. Therefore, black colour is like an obstacle from the colour moving from orange into yellow. In an emotion way, despite the fact that the shape of the canvas is rectangle with less orange area, as if the black area is pulling down the orange, the usage of colours gives people an satisfied situation. Moreover, harmony of colour is given surprisingly with the colour of yellow and black.
On the other hand, Black Square with Blue is more simple and minimal, as they are in minimalism. The shape and arrangement of black and blue can be some things which we can see in real life, but in a more blurry situation or the mind that how people are really looking at things. And for the negative space as the creation of the arrangement, in my opinion, giving audience that the canvas is not just a rectangle or square, we can get more than those.
Moreover, Abstract Expressionism had more diversity on the paintings style with different artist, as they were individuals with different stage of emotion, some of the artworks were more intangible.
To conclude, Minimalism was more simple, with less “madness” and “actions” campared to Abstract expressionism. But they are similar when it comes to emotions and feelings.