It was fun painting at Gasworks Park yesterday. So far, it always is. It's a shame that it was time to go just about when I was all warmed up, though. Do you think you could still make use of the time and attention you put in yesterday and paint a couple more versions of that giant collection of rectangles?
We formed guidelines for color and value, remember?
Most of the compositions stuck the structure right in the middle of the page. That aspect of your next attempt might benefit from some thought.
How about edges? Did you use a mix of hard and soft? If all your edges were hard, chances are the paint was dry by the time you got your next color mixed. If so, try making the first layer a lot wetter, so it will stay wet longer. You could also broaden the range of colors that are acceptable, so you can cut down on how long it takes to make something that will work. It's a pretty forgiving subject, after all.
Take chances. It's all an experiment!