Alright, we know an awful lot of human cultures associate colors with emotions. Now, part of it is actual psychology that we've been able to notice (see Baker-Miller pink and blue lights with crime), some of it has to do with bodily sensations like red with passion, and some of it has to do with the colors that were available in an area. Here's my idea of Vulcan color associations.
RED is the color of Vulcan. It is their sky and their rocks. Red brings tranquility, calms the mind, and allows them to feel at home. It is common to find due to how easy the dye was to make, and that never truly went away.
ORANGE is found in a variety of places, an in between. It is generally a neutral shade, though not one preferred. It used to be a symbol of unease and middling, though that significance has faded. It's mostly meaningless now, lumped in with the first half of a rainbow.
YELLOW is their sun, and their sands. It is heat. Yellow brings clash and disagreements, a color sometimes used to signify seniority or rising above. It can mean wisdom, or anger. The two are not exclusive.
GREEN is blood. It is life. It is passion, being spilled onto sands and onto sheets. Green used to hold weight, a somewhat difficult color due to the amount of plants needed to make it, though now it's a nice compliment to interior design.
BLUE is an incredibly rare color on Vulcan. It does not occur naturally in their plants, and wasn't found to be existing until mining began with gemstones being found. Blue is a color of power, clashing with their warm landscape. It demands attention.
PURPLE is a similarly rare color, though purple could be found occasionally in plant life. Purple was often used as a caution signifier, as the plants that harbor its color are poisonous, bright to stand out against the tones around it.
BLACK is darkness. It is cooling. It is the night, and the absence of relentless fire. It is a place to sit and meditate, and to pay attention in. To listen, and explore, as if no light exists here, then something unknown lays ahead. Keep your feet about you.
WHITE is a color of royalty and high minds. To have pure white clothes was to have it unstained by the rocks and the sand and the dirt, to not have your hands muddied by your work. It has grown into a more common color due to the fact that most Vulcans no longer work with their hands, but it is still seen with slight regard.
BROWN is nature, found in wood and stalks and reeds. It is grounding and beauty. It is one of the most common colors found in architecture, as it is noticeable yet not proud.
As time has gone on, much of the significance of colors has faded. Replicator technology allows access to any shade you could be interested in, as preference is not generally toted as an emotion. However, Vulcans who are old in their ways, or those that study their ancient cultures, tend to hold space for the way these interact, and the inherent power in what the eyes see.
Of course, this is a mass generalization of Vulcan, but this is not the post to get into the nitty gritty details about differences in culture. That’s for another time.
