"If you look intensely at the pure blue of a serene sky, you will see that it is not flat dead colour, but a deep, quivering, transparent body of penetrable air, in which you trace or imagine short, falling spots of deceiving light, and dim shades, faint, veiled vestiges of dark vapour, and it is this trembling transparency which our great modern master (Turner) has especially aimed at and given. His blue is never laid on in smooth coats, BUT IN BREAKING, MINGLING, MELTING HUES..."
So - how to achieve "breaking, mingling, melting hues"? In his excellent "Pastel Pointers" book, Richard McKinley talks about "Fragmenting" the colour or using "fractured colour" in order to create luminosity ....in my books and teaching, I have always talked about "broken colour", but I like Richard's choice of words rather better. Using broken or fragmented colours allows us to give the impression of inner light in our paintings...the painting will almost pulsate, or glow, because by using ANALAGOUS COLOURS (side by side on the colour wheel) OF A SIMILAR TONE TOGETHER WITH THE MAIN COLOUR of whatever it is we are painting, instead of one, flat area of a single colour, we are in fact using all the colours of the spectrum together. As I began this post talking about the sky, let's take the blue of the sky. I have used three blues, one cobalt, one blue which leans towards green (so contains a hint of yellow - the second primary colour) and one which leans towards purple (and so contains a hint of red, the third primary - therefore we are, in essence, using all three primaries together - it helps to think of it in this way. ) .They are all similar in tone, though I think to achieve Ruskin's "faint veiled vestiges of dark vapour", as in his first paragraph, a touch of a darker tone in the mix as well would also work:
|broken colour top left; solid cobalt blue top right,|
the three colours used for the broken colour patch are shown at the bottom.
|Fire in the Sky Pastel on paper 13x16"|
and below, Silver Light at the Beach Pastel on paper 21x26"