WiP of the day - Millais master study

As an exercise suggested in a workshop in the ImagineFX forum, I'm doing a master study of Millais beautiful painting "Sound of many waters". Millais was one of the artists belonging to the Pre-Raphaelite school of painting. The exercise is to try and reproduce a Pre-Raphaelite master work as well as you can, in order to gain a more thorough understanding of its composition, color palette used etc.

Here is the original:

And here is a WiP of my digital chalk (ArtRage) version of the painting. So far I've been using chalk sizes from 100-10% to establish the big overall shapes and color patterns before moving into more and more detail.