Tweaking a fabric color

I am making a landscape quilt - I found this fabric, it seems fitting, but a bit too bright.

I decided to try to darken it a bit - this is what I did:

First I backed part of the fabric with freezer paper - this will stabalize it and provide a water barrier. 

I chose Black, Prussian Blue, and Dark Hauser Green, along with a transparent extender.  I spritzed the fabric with water so the paint would be loose.  I used a sponge to spread the paint and then kind of wiped up the extra paint. 

This is the result - showing the difference between the painted piece and the original color. 

We'll see how well it works as my project progresses.