http://www.conceptart.org/forums/showthread.php?p=1257287#post1257287
David:
Hold on, on your wheel "RCW#4 = Benzimidazolone Orange PO 62" and "RCW#22 = Cobalt Blue PB28" are opposites, and you're saying when these are mixed together they will give me a substitute for black? That would be the grayest black I've ever seen.
Don:
I'm very pleased with your question David, you are aleart and paying attention.
Opaque colors will still mix neutral, but not as dark as transparent colors mix. As an example, transparent magenta and transparent green will mix very dark. One opaque and one transparent will also mix very dark, like opaque red and transparnet cyan.

The balance is more critical with one transparent and one opaque, more than two transparents or two opaques. On the up side of orange and cobalt blue mixed opposition is their ease of balence. Thay have a much wider range and ability to hold the neutral. If I were to paint a neutral full gray painting like a griselle, this is the combination I would use.

NEW POST 3-20-7

David said,
"What bothers me about your wheel layout, Don, is that it's a value range in 2D space rather than a saturation scale to neutrals."

Don: It has a saturation scale to neutral on every colorwheel I have. It just doesn't go straight to black like all other colorwheels do.

Don:
The RCW has 10 divisions before black and 10 to white. That's a nice saturation or chroma to the neutral dark and light scale. The difference being my colors get darker by adding the opposite color which make dark browns and blues before getting to a black neutral color.

David:
"This makes it rather limited and misleading in the display of complement mixes. I've seen a few other color wheel designs, and they typically run from pure chroma to gray along the axis, which is more true of how opposites mix."

Don:
I don't agree with that statement at all.
Yellow, in pigments does not darken with black, dark yellow is not dark greenish gray as it would be in mixing pigments and on Munsell's (renotated) RGB color wheel. The same goes for cyan. Dark cyan is not greenish gray, it's blueish, like the sky at it's azimuth. There is no gray in it's value and it's chroma does not lose color.

All 36 of the RCW colors mix neutral with their opposite color, that's the way they were made, that's the chroma scale that is shown.  These colors are not made by adding black or gray. The RGB and Munsell yellows, oranges and cyan's all lean to the green side. Black and yellow pigments mix green, and black and yellow in light have the same greenish cast to them. Yellow does not get darker adding black pigment, it stays warm and gets browner.

David:
"Also, these other layouts show more pigment matches; about twice what yours is showing. Stephen Quiller and the Handprint version come to mind. The Munsell model has a more practical representation of values in 3D space, says David."

Don:
Practical as in a straight line to black, not practical for the artist that doesn't use black pigment.

Don:
Quiller's Wheel uses different primary and secondary colors than I do.
On his color wheel, magenta is a tertiary color and Phthalo Green is not opposite to it, His primary magenta is PV19, which makes his red also warmer then I think it should be also. Ultramarine Violet is one of his secondary colors and ultramarine blue is a tertiary.

HandPrint uses the same color arrangement as my color wheel and places colors inside their RB format. It's very good and locates all color pigments, there in a different location than mine. I have 36 colors and match pigments in them as the 36 colors get darker according to the way those color elements get darker.


Here is Munsell from the Handprint page, a very good reference site. Even though I don't agree with anything about the Munsell Color Tree.
http://www.handprint.com/HP/WCL/color7.html#munsell

From their page..
"The Munsell Color System is arguably the first modern color order system — based on the three colormaking attributes, and implemented through careful color measurement. Conceived in the 1890's by the American artist and educator Albert H. Munsell 1858 to 1918, it was described as a theoretical color model in 1905 and exemplified as a 15 page atlas of color samples in 1915. (This was extensively revised and republished in 1929 as the Munsell Book of Color, comprising 20 hue pages that each contain about 20 color samples.) The Munsell system was extensively revised or "renotated" in 1943, when it was adopted as the standard color reference system in the USA. It remains one of the most popular and widely used color order systems."

Don:
Here they show a color model image that was probably made in or about 2005 showing the colors magenta and cyan. Colors that were not available in 1943, All the colors are in the right place now but the names have changed to make it work. From the original 5 colors, 10 were made. Yellow and Red now have an orange between them, that's good. Red and Purple have a bigger problem, a Red-Purple has been added. Red and purple won't mix into a magenta, but that's were the new color magenta is placed. Fine.. since the goal now would be to convert us to call magenta, red-purple say it made from mixing red and purple.

Between Purple and Blue there now is a Purple-Blue. The original Munsell Blue has changed hue from ultramarine blue hue to cobalt blue hue. Now it works.. Purple-Blue is the new ultramarine blue on Munsell but they still call the old Blue in the same place ultramarine blue, and the new color Purple-Blue.

Another new color was added between the old Blue and Green, well blue and green won't mix into a cyan but that's where cyan was placed, and that's where cyan should be. Munsell had no primary pigment cyan at the time, the best he had was a dirty Prussian blue which didn't work as a primary at all and he didn't call it so. Lastly, between Green and Yellow they added Green-Yellow. Now with their full 10 colors the US adopted the Munsell color system.

Wait an minute.. on a 360 degree circle, red is 60 degrees from magenta toward yellow and purple is 30 degrees from magenta toward cyan. The middle of those colors is not magenta, it's not even close to magenta. There are 2 color spaces between yellow (Y) and red (R), 1 color space  between red (R) and magenta (RP), 2 color spaces between Magenta (RP) and ult. blue (PB), 2 color spaces between ult. blue (PB) and cyan )BG), 1 color space between cyan (BG) and green (G) and 2 color spaces between green (G) and yellow (Y).  That's very lopsided.

I think the US bought a bag of worms back in 1943.
This is not the Munsell color wheel any more, it's a lopsided RGB color wheel, and look.. the colors get dark the same way, just add black. Why do they still call it the Munsell (renovated or renotated) colorwheel? It has no relationship with the original Munsell color tree.

How about the Blue-Green that is supposed to be translated into cyan.. Everyone knows blue and green won't make cyan, cyan can't be made because its primary. But for the sake of overlaying the RGB colorwheel, cyan is between Blue and Green. That's where it should be. Blue, the new Blue which is cobalt blue hue and green are 72 degrees apart on Munsell. On the 360 degree wheel, Green is 60 degrees from cyan and cobalt is 30 degrees, the middle of those colors is not cyan as they claim.

But, if we play the old "pea" game and you call Munsell's old ult blue the same name but change the color to cobalt blue and add a new color and call it Purple-Blue but use the old ult blue color. That would work, it wouldn't be the old Munsell color wheel but you could call it the new "renotated" Munsell color wheel. Now if you could just make people call magenta, Red-Purple, and ultramarine blue, Blue-Purple, and cyan Blue-Green you could sell it, to some of the people some of the time.

HandPrint:
"At the middle value level is a hue circle defined by FIVE EQUALLY SPACED HUE DIMENSIONS — red (R), yellow (Y), green (G), blue (B) and purple (P) in clockwise order (yellow at the top, red on the left). These principal colors are separated by five mixture hues between them — yellow red (YR), green yellow (GY), blue green (BG), purple blue (PB), and red purple (RP) — each the visual complementary color of the principal hue directly opposite it. These principal and mixture hues divide the hue circle into ten equal hue segments, and each hue segment is again divided by ten (counted in the clockwise direction), resulting in a 100 step hue circle. The "standard" or central example of each color segment is located at step 5 (diagram, right).
Finally, each hue was calibrated in equal chroma steps from zero (pure gray) to the maximum color intensity in the paints or inks used for each hue; in the idealized (aim) colors, chroma intervals are calculated out to the optimal color limits.

The early measurements were made by the USA National Bureau of Standards, which took an interest in developing the Munsell system as a color standard. In the 1930's the Optical Society of America also began a technical study of the system. The entire 1929 Book of Color was measured spectrophotometrically in 1935 and published as Yxy values in 1940. These revealed major discrepancies between the 1915 and 1929 color samples, and major irregularities in the spacing of color samples on the Yxy chromaticity diagram, particularly in the chroma intervals but also in the lines of equal hue.
The OSA committee primarily focused on defining the Munsell value scale as a mathematical formula, based on visual judgments of gray samples by a large sample of viewers, and on judgmentally adjusting or "smoothing" the contours of Munsell hue and chroma on 1931 xy chromaticity diagrams. These calculations were used to revise the value scale, to equalize the hue and chroma intervals, to extend chroma intervals out to the optimal color limits, and to redefine material color specifications. This renotated system was published in 1943 as specific Yxy values for 2700 unique color locations, as a mathematical formula to calculate Munsell value from XYZ tristimulus values, and as several 1931 xy chromaticity charts used for the visual estimation of Munsell hue and chroma values from xy values. Subsequent editions of the Book of Color are blended to match these 1943 targets. The renotated system is the standard specification of Munsell colors used today."

Don:
So that's it, how the "renotated" Munsell color wheel became the Red, Yellow and Blue color wheel. The schools still teach it according to all of their States School Standards rules.

The next step is to make colors darker by using the opposite color, not black pigment or light. That's what the Real Color Wheel does.

Just as a side note, both HandPrint and I found a flaw in the light time tests reported for PV19 and PR122. PR122 is permanent in lime fresco also.