No problem to make it lighter. Seems I’m used to autumn/winter being rather dark seasons … I’ll test a lighter shade to see if that looks better. (Winter I have configured off currently, I’m fed up with having real winter, that’s bad enough).
It should probably look greener, not lighter. You might be able to mix in patches of green/brown grass instead of using solid colors, but it might be hard to get that to look right.
The seasonal plant cycle thing is cool. Are they animated or does it pop between one state and the next?
As I wrote in the other thread, this is AWESOME! Really cool!
I love your tools. Man, if I was to make those, I’d be spending years…but then you have a lot of experience with Swing. Love your scroll-bars 
There is only limited animation. Plants can be made with any number of frames, which are spread through the year, but in the demo there are only 3 to 7 frames per plant, so the changes from one state to the next are quite strong.
Thank you very much, but it’s really not that special
Most of my stuff has old roots. If you’ve been toying around with games, tools and demos for 15 years or so, you just have a big repository of code snippets which you can reuse. And the scrollbars are just from the “Nimbus” look and feel that comes with Java since a while 
http://sourceforge.net/projects/freemapper/files/Greenspace/r6/
It’s the latest release, nothing strikingly new, just a more rounded version.