No, it’s not watercolors. Actually, I made the lineart with ink, then scanned it; then proceeded with digital colouring (flat), then printed on cream-coloured paper; then used colored pencils (for the shades) over the printed resut. I’ve just published a scheme of my process here: xixdeviant.deviantart.com/art/…
It's not watercolors, but pencil, ink, digital colouring (flat) and, finally, pastels (for the shades) over the printed result.
It was done for nobody else, it's basically a vision of a poster for some sort of 19th century-medicine (more precisely, I chose plants assigned to the cure of the anemia: cress, nettle, wormwood, dogrose berries…) – the whole concept is about the duality between flourishing beauty and weakness/vulnerability.
Unfortunately, the model doesn't exist - at least in the real world - she's only a product of my own mind (sigh).