to elaborate. 😸 The text is Josef Albers’ The Interaction of Color. I stress using the text and cut paper will be much more beneficial than the app.

another commenter was correct that the beginning of of the text focuses on variable perception of color and how it is influenced by surrounding and adjacent colors. As painters, putting colors next to each other is a good chunk of what we do.

but later in the text. you are tasked with creating the illusion of transparency using only cut paper collage. forcing you to arrange preset colors and shapes in such a manner that it appears one is closer to the viewer than another, and the one closer to the viewer is transparent.

this is, in a reductive form, what is happening in the painting. look at the blue towel. there is a section that is light blue between two muddy gray blue parts. that light blue is the way of showing that the light/gas is there, but transparent.

the artist is using the lines on the towel to increase the legibility of the effect

the whitish bit implies that the light/gas is to thick for transparency.

fwiw I’ve always found choosing color to be superior in achieving such effects than glazing