The Green of the Rhone

Ruskin (in TWS p 115-116):

Rhone has been green all day instead of blue. Looking through it, the colour is decided green; but along the surface it is blue - very like fluor spa. Notice effect: reflection taking off light from ripple, shows in transparent green, very slightly affected by colour of object. The chimney of steamer opposite is rich brown inclining to red, but its reflection is still green, a little dirtied by the red colour.