ICI and Glidden share a palette or two so that color number works for either brand.

Those numbers represent hue, LRV and chroma. The first set indicate value on a scale of 00-99 within a color family. So YY is Yellow-Yellow. This notation isn't always clear with some colors unless you are familiar with the colorants used to mix the colors.

The second set is the LRV. The higher the number the lighter the color, the lower the darker the color. 83 tells me it's a light color whereas 10 would tell me it's a really dark color.

The last three represent the chroma of the color. The higher the number the more intense and a lower number being an indication of a more muted tone. So 21 tells me this is a *soft* color, not vivid.

40YY 83/021 is in the current color decks with the name Minimalist White - perhaps it is the same color, just an updated name.

funcolors.
Thank you so much for that explanation and also the new name of that color.
That helps alot and now I understand somethig that I have always wondered about.