Experience

As far as the composition and color go, the point of focus is clearly the central smears. It's simple but meticulous and very balanced and symmetric aside from the smears, as seen by the grid. The silver in the background is very metallic, meaning that the painting is almost a function of the light shined on it. From the light at the museum, the purple circles on the top right looked like they were black as opposed to the ones on the bottom left. Depending on where I stood in relation to the painting, the some purple circles would look black to me. 

And as for tone, I saw a contrasting tone. I saw a dark tone as the main one because of the dark purple and black circles that seemed like they popped out, and then I saw a light undertone because of the reflection on the silver. And finally, it seemed a contrasting, but complementing tone because as the silver shined brighter, the dark circles seemed even more radiant than before. The tone also seemed dramatic because of the smears. On such a big canvas, she must have had dramatic movements to create the smears.