Orange Tree vs Purple Tree

Continuing with our color studies here's a color combination that does work and another that really doesn't work, and I'll tell you why.

"Alone" a warm color tree on a dark background.

In the top image the orange/yellow tree sits on a warm bright yellow field and the background is a blackest green row of trees. The tree and field move forward and the background drops back as it should.

"Alone purple" 

Have you heard the saying "shrinking violet"? 

Generally the color purple drops to the background especially if it's a cool purple, and red, a bright warm color moves forward. 

The color combination with the purple tree doesn't work because the purple tree drops back and red background comes forward. 

The light purple field and the purple tree want to drop into the background. The warm yellow sky moves forward. 

So this color combination not only doesn't work it is jarring with shapes and colors moving back and forth. It works if the artist's purpose is to create a design that disorients the viewer.