When I was about 9 or 10, my mother took me to the eye doctor. He told me to look at a page of different colored circles, each about the size of a bead, and asked what I saw. No problem. I saw the shapes and patterns clearly. Or so I thought. Actually, I saw the "wrong" shapes and patterns, the ones you see if you are color-blind. That's when my mother figured out why I sometimes wore one blue sock and one black one.
Being color "blind" doesn't mean one cannot see colors, except for a rare form of the malady. Rather, most color-blind people (usually boys and men) see colors a little differently. For example, it's hard for me to discern hues of color, say purple as opposed to blue or tan instead of brown. I was an adult before I learned a "green light" was actually green; growing up, I thought the light was white, like the light bulbs in a house; the "green" part I took to be a reference to a bygone age when traffic lights were actually green. (To tell you the truth, I'm still a little suspicious about this one. Grass is green; I can't believe a traffic light is that color.)
Fortunately, the liturgical colors that mark the passing seasons of the church year are primary colors, rich colors, colors so close to the center of the target even I can see them aright. Since Easter, the cloth on the Communion table and hanging from the pulpit has been white, the color of joy and victory. The earliest Christians marked their baptism with a white robe, as we do still today.
This Sunday, Pentecost Sunday, the color of the cloths ("paraments") will change to red. Red is the color of fire and commemorates the "tongues of fire" that fell on the early church at Pentecost (Acts 2:3). Since red is also the color of blood, red paraments are used on Palm or Passion Sunday marking the beginning of Holy Week and on Good Friday.
If you don't like change, then settle down because Sunday week, the liturgical color will shift to green and stay way throughout the Pentecost season, the seventh-month period that carries us all the way to Advent.
Since the fourth century when Christianity became legal in the Roman Empire, many churches marked the changing seasons of the church year with colors. Why? Perhaps because God does, changing the colors of the world with the changing seasons: green in the spring and summer, gold, red, and yellow in the fall, and sometimes white in the winter.
Liturgical colors are simply another way of telling the Gospel story, enhancing the beauty and symbolism of worship, and affirming our kinship with the larger Christian church. And the really great part for color-blind people like me, is that these colors are so rich and full, we can actually see them!