As I continued to work on the exterior paint color charts for the Riviera Project, I have been thinking about arranging the colors I display. I’ve been trying to sort visually using ROYGBIV, with some degree of success. After a few months, a seemingly obvious concept finally came to mind—why not just use the color hue values to place them?
I’ll expand: one of the many ways to describe a particular color is the HSB color space—Hue, Saturation, and Brightness. Also named as HSL (Hue, Saturation, and Lightness), HSB is a different way of measuring the RGB color space. The interest here is that it nicely separates hue from other color factors over 360 degrees, with the red in ROYGBIV starting at about 345 degrees.
HSB was initially conceived as a way to add color to black-and-white television transmissions without changing the signal that the black-and-white sets were receiving. It has been around for quite a while—French engineer Georges Valensi invented it in 1938, pre-dating the first consumer color televisions by 16 years. Those first color televisions were astoundingly expensive—the Admiral C1617A’s $1,175 price (about $11,200 in 2020 dollars) gives a hint of why substantial color television adoption would take almost 15 years.

So far, I’ve charted the exterior colors using the print-oriented CYMK color space. Still, Adobe Illustrator (which I’ve been using) and a plethora of other applications have no trouble converting the values displayed to HSB so that I can see the hue value. It was time for some testing—what could go wrong?
I tried this new-to-me color sorting method out on the current beta of the fifth-generation chart. It seems to work decently, but more exploration will be needed. The early results are shown to the right.
While I’ve been testing these sorting revisions, I’ve added the appropriate Buick-assigned two-digit color number and an asterisk if the color is metallic to each paint swatch. So, the charts now also have higher data density.
The charts also show the somewhat confounding color naming inconsistencies that prevailed throughout the Riviera’s life. A color can keep the same marketing name (i.e., Medium Green), but be a different painting formulation (changing from PPG 2694 to PPG 3062). Another color can alter its marketing name but remain the same paint formulation. Finally, the same Buick-assigned color number (63) can change paint formulations (PPG 2970 to PPG 3090) and color names (Gold to Dark Gold) from year to year.
Details, details, details, …