Spring Bud

And so it is April, the first full month of spring.

Spring and autumn, at least here in the mid-Atlantic part of the United States, are all about bright color. The colors of summer, while varied, tend to be more muted, and the palette of winter's colors, at least outdoors, tends to be a monochromatic mix of blacks, whites, grays and browns.

We human beings have been able to discern color since our ancestors evolved in ways to achieve tricromacy, meaning that our ocular systems have three different receptors that receive color. This works out nicely for perception of the three "primary" colors, (either red, blue and yellow, or red, blue and green), and the rest of the color spectrum that derives from them.

It is thought that the ability of humans to detect color came about as a response to the need to find food sources when life is lived in daylight. Nocturnal animals, or animals that live deep in the ocean, cannot perceive color as well as land animals because light is necessary for the color-sensing systems of the eye to work. But for diurnal creatures, it is pretty important to be able to tell the difference between the intense red of the poisonous holly berry and the indigo of the delightful blueberry.

Sir Issac Newton discovered that color is an attribute of light waves when he split light into colors by the use of a prism, and recombined them back into white light by the use of another prism and a lens. He also originated the tradition known as "color theory" and invented the color wheel.

Apparently discovering gravity and inventing calculus wasn't enough for Sir Isaac; perhaps he had a yen to be an interior decorator as well, to wit: "Faugh! Art thou mad? Thou knowest that heliotrope doth not go well with turquoise!"

Since then, color theory has evolved to help us understand the nature and uses of color; which colors complement each other, what psychological effect is created by a color. Human eyes can detect approximately 10 million colors, a lot of shades to work with (not to mention naming them - remember the big 64 color Crayola box, with burnt sienna and periwinkle?)

It is interesting that lots of color names derive from edible things - orange, peach, lime and lemon to name a few. Also aubergine, the gorgeous French word for the purplish-brown eggplant.

There are two fundamental ways to create color - by addition, as with light, or by subtraction, as with pigment or paint. Essentially, to create color with light you start with darkness, and add colored light to reach white light (add a blue light to a yellow light and the result will be green; add in a red light and you will get white.) When dealing with pigment or paint, you start with white, and remove colors on the spectrum by using a pigment that absorbs or blocks everything except a specific color wavelength; whatever shows through is the color of the paint (for example, cobalt blue paint absorbs every color except cobalt blue.)

Differentiations between the two methods of creating color have caused some difficulty in the creation of a coherent theory of color usage. However, generally speaking, in color theory there are three attributes used to describe a specific color: hue, saturation and lightness.

Hue translates to the basic color itself - is it a variation of blue, of yellow, of red or green? Saturation refers to the intensity of a color. Lightness, of course, has to do with the amount of light versus darkness in a color.

Of all of the seasons I think that Spring has the most saturated colors. Could there be a more intense yellow than a daffodil?

But if April had a color, for me it would be chartreuse, a tertiary color. Chartreuse is defined as being halfway between green and yellow on the color wheel. It happens to be one of my favorite colors, because it just looks good enough to eat.

The color of key limes, and the pie that is made from them. The earliest buds on the trees, no doubt tasty to some foliage eater. Those little tiny pea shoots peeking up in the garden.

Look around you - at the blooming forsythia, a saturated yellow with just a tint of green that could be called citron; at the young willow switches, more chartreusey; at the new grass, an intense velvety verdant carpet that looks so soft you just want to roll on it forever, and maybe munch some, if you happen to be a cow.

Soon green will give way to magenta, as the redbuds come into their own, and tulips will bring everything from reds to oranges to silky black to the spring palette. And the incredible edible pansies will add violet and blue as well as yellow.

Next week the cherry tree on the front lawn will pop with pink. But for now, the chartreuse landscape is feast enough for my eyes.