Merriam-Webster’s online dictionary defines “cool” in seven ways. For this challenge, my examples primarily relate to their number 6, which references color, “Specifically: of a hue in the range violet through blue to green.” However, my challenge is open to all interpretations, so if you have an image that meets one of the other definitions of the term, you’ll get no arguments from me about using it.

Cool colors evoke calmness, serenity, and tranquility, feelings often associated with water, sky, and nature. About eight years ago, we stayed overnight near Turtle River State Park in North Dakota. I was up early for the blue hour, and as sunrise approached, the darkness gave way to violets and greens.

While looking for examples containing cool colors, I rediscovered my photo collection from that morning’s walk. I remembered that unusual morning when I saw those pre-dawn images bathed in violet. The skies cast a violet light through the cloud layers, a rare sight for me. I found the originals and reset the Adobe Lightroom adjustments I’d made to confirm that I hadn’t emphasized the violet in my post-processing. The original RAW files match the colors in the images above. Purple conveys luxury, creativity, mystery, and wisdom.

As the sun began to peek above the horizon, that eerie purple sky slowly transitioned to yellow, appearing to light the trees on fire. However, the transition was short-lived. The sun went behind that relatively thick cloud layer only a few minutes later.

Let’s examine the science behind cool colors. The “coolness” of these colors is linked to the wavelength of light. Cool colors have shorter wavelengths than warm colors (red, orange, yellow). In February, Egidio hosted a Warm Colors challenge focused on the longer wavelength end of the color spectrum.

The warm color of the monarch’s wings adds warmth to a cool “garden” of thistles. The color contrast in this image helps the subject stand out from the environment. Green represents growth, harmony, freshness, and balance. It’s associated with nature and renewal.

The designer attempted to create a soothing atmosphere with this Ford Edsel’s blue interior. Blue evokes feelings of trust, loyalty, intelligence, and stability. Unfortunately, Ford Motor Company apparently didn’t make enough blue Edsels.

Though I like blue as a color choice, I’m not a fan of blue sports cars. Mustangs, Camaros, and Corvettes are “hot” cars and should be cloaked in warm colors, but your opinion may vary.

My opening images featured a slow transition between cool and warm colors as the sunrise approached. On arrival in the Dominican Republic via cruise ship, the transition between blue and golden hours was much more abrupt.

Thank you to Sofia, who hosted with Sense of Scale last week. Next week, look for Anne’s challenge, which will be posted at noon EST on Saturday. Be sure to follow her here so you don’t miss her challenge. If you’d like to post a challenge response but aren’t sure how to get started, here are the details.

John Steiner