Part 2 – The (Brown) Colours of the Rainbow
As for colour – nothing is barred. The breeders still strive for true scarlet, true blue. Meanwhile gardeners can be thankful for the soft spectrum of rainbow colours: Iris, after all, was goddess of the rainbow. The standards and falls may be different colours, or different shades of the same colour, or they may be a uniform colour all through…Now the pink iris takes its place amongst the lilac, the lavender and pearly-grey, the clear yellow, the heliotrope and the deep violet and indigo…and finally what E.A. Bowles called ‘thunderstorm bronzes and lurid buffs’.
–From Irises and Other Flowers, Watercolors by Elizabeth Blackadder & Commentary by Deborah Kellaway
I haven’t seen any lurid buffs in my garden, but it is curious how the colours shift during the course of the day and throughout the blooming period of a flower. This has been especially true of the brown irises (Dutch iris ‘Eye of the Tiger’), which sometimes seem to be brown and sometimes seem to be maroon or violet. This puzzled me for quite awhile: how can a colour switch from a purple hue (blue + red) to brown (a toned orange: yellow + red)? Finally, I remembered the section of the “Understanding Colour” class that dealt with “tints” and “tones”. A tint results from mixing a colour with white, which increases lightness. A tone results from mixing a colour with grey or by mixing a colour with its complement.
Isaac Newton’s color wheel is often used to describe complementary colors, which are colors which cancel each other’s hue to produce an achromatic (white, gray or black) light mixture. Newton offered as a conjecture that colors exactly opposite one another on the hue circle cancel out each other’s hue; this concept was demonstrated more thoroughly in the 19th century. . .Any color that lacks strong chromatic content is said to be’unsaturated, achromatic, or near neutral’. Pure achromatic colors include black, white and all grays; near neutrals include browns, tans, pastels and darker colors. Near neutrals can be of any hue or lightness.
For the three primary colours (blue, yellow and red), the complements are orange, purple and green, respectively:
- blue + orange = grey or brown
- yellow + purple = grey or brown
- red + green = grey or brown.
When I looked closely at the section of a colour wheel depicting watercolour pigments, it was clear that the colour shift from Mars Violet, Venetian Red or Perylene Maroon to Burnt Umber was very slight. And when I started mixing paints, this became even more clear. Using the colours of the rainbow (red, orange, yellow, green, blue, indigo and violet) I mixed each colour with its complement, resulting in a “greyed” rainbow, as shown below: