This is beautiful!! As for coloring you could always try both. Color the original with watercolors and the digital/scanned copy with a tablet. This is a really gorgeous piece!!
You should make the colors weird. Like.. Instead of green trees they be purple or something. As if you were on a different planet But on a more serious note, this is amazing. And I love how it look's like the mountains are all around her and this giant one just pops up out of nowhere. And it kinda looks like someone was laying in the grass taking a picture of her with a fish eye lens It looks really cool.
Non ho parole *^* penso che sia perfetta l'idea di colorarlo con gli acquarelli...permetterą di non disperdere il disegno primario, che č meravigliossso. Buon lavoro ;D