Stuck with 32x32? Hmm. Yeah, you may be interested a bigger character, if possible. I still think his puny size is a bit awkward. I still wouldn't worry about detailing too much as what I think is most important is that the player can tell what they're looking at. Besides, I've seen too much 'meh' artwork that focuses too much on detailing and not the big picture - stuff brought up like color choice and character design, and the overall art style. I feel it's possible to drop some needless detailing especially on the weeds so they're easier to read.
As for suggesting details not literally there, in the case of styles I posted earlier, I would say that it's mostly drawing only a few details you're able to fit in. Even 32x32 is far too small for a hyper-realistic grass tile (not that I've seen any at that size). Look at the character's hand. It's like four pixels wide. The smallest literal piece of grass you can possibly pixel is no thinner than a quarter of his hand. That's huge, since grass is supposed to be much, much thinner. That's how pixel art is... it really helps to toss out less important details you can't really fit in a small size. We're not stupid - we can easily fill in gaps of missing information anyways.
You're totally right that shifting your hues will add contrast, but luckily hue contrast isn't the only contrast available. You can just change your value contrast if the hue-shifting creates too much contrast. Besides, it's a bit lifeless to have hues not move anywhere especially outdoors when you have a warm-colored sun and a cool-colored sky creating warmer lights but cooler shadows. Maybe with overcast weather things become more monochromatic, but even then there will be colored objects giving off colored light and such. I find the newest revision to be more appealing overall and without contrast issues. Then again, I dunno how it presents on your particular monitor though.
I wouldn't worry too much about blues turning into blacks... not that I know how your day/night system would change things though.