A very light and whimsical soundtrack with good instrument selection and arrangement, they all fit the ideas you're trying to convey. The composition and story telling were great, it really captured the emotional journey of the setting, I could see myself stepping into the painting and going on an adventure. I'm going harp on about some technical aspects of the mix now, please bear with me, its longer than my compliments only because I'm digging into the details, overall I really enjoyed the listening experience. The library you've chosen sounds a little dry when only a few instruments are playing, adding more reverb and subtle saturation should give it a nice boost. Another thing I'd try to do add extra instruments to the parts where the song sounds sparse, you can just let them play a simple accompanying part at quite a low volume, it sacrifices some contrast but it fills up the gaps in the frequency spectrum.
The cymbal crash at 0:28 in The Painted World of Trifolia is a little short and it doesn't sound very glued together (could be a compressor overreacting but it also can just be using the wrong crash sample), the reverb and saturation I suggested earlier would help, but you can add a little extra reverb to the cymbals directly if you need it to last longer. Applying some subtractive EQ to carve out from space from the tonal instruments during this impact can also glue the mix and give the drums and cymbals more weight while reducing the chance that the compressor/limiter overreacts.