Rock-Color Chart
All 115 chips of the geological Rock-Color Chart with their Munsell notation, color name and screen HEX. Type a notation such as 5YR 4/1, or find the chip closest to a color. These are screen approximations of the notations, not a replacement for the printed chart.
Notation to name and HEX
Name in the chart
Brownish Gray
HEX
#6A5E58RGB
rgb(106, 94, 88)Screen approximation of 5YR 4/1, not the printed chip.
Color to closest chip
- 5Y 5/2 · Light Olive Gray
#817961ΔE 5.2 · Approximate - 5YR 5/2 · Pale Brown
#8A7569ΔE 5.9 · Approximate - 10YR 6/2 · Pale Yellowish Brown
#A1917DΔE 7.3 · Distant
A color from a photo is only a hint: light, camera and a wet or dry surface change it more than one step of the chart.
The chart by hue
Chips go from light to dark within each hue. A dashed outline marks a color more saturated than a screen can show; its HEX is the nearest screen color.
Red (R)
- 5R 8/2Grayish Pink
#D6C4C2 - 5R 7/4Moderate Pink
#CFA39F - 5R 6/2Pale Red
#A48E8D - 5R 6/6Light Red
#C4827E - 5R 5/4Moderate Red
#9B6E6C - 5R 4/2Grayish Red
#725A59 - 5R 4/6Moderate Red
#8F4D4C - 5R 3/4Dusky Red
#693A3B - 5R 2/2Blackish Red
#412B2D - 5R 2/6Very Dark Red
#571D28 - 10R 8/2Grayish Orange Pink
#D7C4BE - 10R 7/4Moderate Orange Pink
#D0A395 - 10R 6/2Pale Red
#A58E88 - 10R 6/6Moderate Reddish Orange
#C4846F - 10R 5/4Pale Reddish Brown
#9B6F62 - 10R 4/2Grayish Red
#735B55 - 10R 4/6Moderate Reddish Brown
#8E4F3E - 10R 3/4Dark Reddish Brown
#683C33 - 10R 2/2Very Dusky Red
#412B29
Yellow-red (YR)
- 5YR 8/4Moderate Orange Pink
#E9C0A2 - 5YR 7/2Grayish Orange Pink
#BFA99C - 5YR 6/4Light Brown
#B38B71 - 5YR 5/2Pale Brown
#8A7569 - 5YR 5/6Light Brown
#A46D46 - 5YR 4/4Moderate Brown
#7F573F - 5YR 3/2Grayish Brown
#584338 - 5YR 3/4Moderate Brown
#633F2A - 5YR 2/2Dusky Brown
#3F2D25 - 10YR 8/2Very Pale Orange
#D6C6AF - 10YR 8/6Pale Yellowish Orange
#ECC181 - 10YR 7/4Grayish Orange
#C7A97F - 10YR 6/2Pale Yellowish Brown
#A1917D - 10YR 6/6Dark Yellowish Orange
#B68C50 - 10YR 5/4Moderate Yellowish Brown
#92744F - 10YR 4/2Dark Yellowish Brown
#6E5D4B - 10YR 2/2Dusky Yellowish Brown
#3C2E21
Yellow (Y)
- 5Y 8/4Grayish Yellow
#D6C891 - 5Y 7/2Yellowish Gray
#B6AD92 - 5Y 7/6Moderate Yellow
#C2AD5E - 5Y 6/4Dusky Yellow
#A29361 - 5Y 5/2Light Olive Gray
#817961 - 5Y 5/6Light Olive Brown
#8E782C - 5Y 4/4Moderate Olive Brown
#6F5F30 - 5Y 3/2Olive Gray
#4F4733 - 10Y 8/2Pale Greenish Yellow
#CBCAAA - 10Y 7/4Moderate Greenish Yellow
#B3B078 - 10Y 6/2Pale Olive
#969579 - 10Y 6/6Dark Greenish Yellow
#9A9743 - 10Y 5/4Light Olive
#7E7C48 - 10Y 4/2Grayish Olive
#626149
Green-yellow (GY)
- 5GY 7/2Grayish Yellow Green
#AAB194 - 5GY 7/4Moderate Yellow Green
#A6B47E - 5GY 5/2Dusky Yellow Green
#767C65 - 5GY 3/2Grayish Olive Green
#444A38 - 10GY 7/2Pale Yellowish Green
#A0B39D - 10GY 6/4Moderate Yellowish Green
#7A9D76 - 10GY 5/2Grayish Green
#6E7E6C - 10GY 4/4Dark Yellowish Green
#486847 - 10GY 3/2Dusky Yellowish Green
#3E4B3E
Green (G)
- 5G 7/2Pale Green
#99B4A5 - 5G 7/4Light Green
#85B99E - 5G 6/6Brilliant Green
#54A27F - 5G 5/2Grayish Green
#687F73 - 5G 5/6Moderate Green
#3B8767 - 5G 3/2Dusky Green
#3A4C43 - 10G 8/2Very Pale Green
#B0CFC4 - 10G 6/2Pale Green
#7E9990 - 10G 4/2Grayish Green
#4E655E
Blue-green (BG)
- 5BG 7/2Pale Blue Green
#96B4AF - 5BG 6/6Light Blue Green
#3FA29A - 5BG 5/2Grayish Blue Green
#647F7C - 5BG 4/6Moderate Blue Green
#006D69* - 5BG 3/2Dusky Blue Green
#354C4A
Blue (B)
- 5B 8/2Very Pale Blue
#B6CCD1 - 5B 7/6Light Blue
#67B9CD - 5B 6/2Pale Blue
#81979D - 5B 5/6Moderate Blue
#2D849A
Purple-blue (PB)
- 5PB 7/2Pale Blue
#A7AEB9 - 5PB 5/2Grayish Blue
#737A86 - 5PB 3/2Dusky Blue
#404857
Purple (P)
- 5P 6/2Pale Purple
#98919D - 5P 4/2Grayish Purple
#665D6C - 5P 2/2Very Dusky Purple
#372D3C
Red-purple (RP)
- 5RP 8/2Pale Pink
#D2C4C8 - 5RP 6/2Pale Red Purple
#A18F94 - 5RP 4/2Grayish Red Purple
#6F5B62 - 5RP 2/2Very Dusky Red Purple
#3F2B35
Tinted grays (chroma 1)
- 5B 9/1Bluish White
#DAE5E8 - 5YR 8/1Pinkish Gray
#D1C6BF - 5Y 8/1Yellowish Gray
#CCC8B9 - 5GY 8/1Light Greenish Gray
#C6CABA - 5G 8/1Light Greenish Gray
#BDCBC3 - 5B 7/1Light Bluish Gray
#A5AFB2 - 5YR 6/1Light Brownish Gray
#9D918B - 5Y 6/1Light Olive Gray
#989386 - 5GY 6/1Greenish Gray
#919588 - 5G 6/1Greenish Gray
#8A968F - 5B 5/1Medium Bluish Gray
#717B7E - 5YR 4/1Brownish Gray
#6A5E58 - 5Y 4/1Olive Gray
#646054 - 5GY 4/1Dark Greenish Gray
#5E6257 - 5G 4/1Dark Greenish Gray
#58635D - 5YR 2/1Brownish Black
#392F2B - 5Y 2/1Olive Black
#343028 - 5GY 2/1Greenish Black
#2F322B - 5G 2/1Greenish Black
#2B332F
Neutral grays (N)
- N9White
#E3E3E3 - N8Very Light Gray
#C8C8C8 - N7Light Gray
#ADADAD - N6Medium Light Gray
#939393 - N5Medium Gray
#797979 - N4Medium Dark Gray
#606060 - N3Dark Gray
#484848 - N2Grayish Black
#313131 - N1Black
#1C1C1C
Where the list comes from
The Rock-Color Chart was prepared by the Rock-Color Chart Committee, representing the U.S. Geological Survey, the Geological Society of America and other geological bodies, and is now produced by Munsell Color as the Munsell Rock Color Book. Its chips were chosen from studies of more than 1,300 rock specimens. The notations and names here follow the 2009 edition. Every notation was checked against the committee's preliminary draft of July 1947, a U.S. government document: 113 of the 115 appear there, and two misprints of the 2009 booklet (5Y 8/4 and 5Y 3/2 printed among the 5YR chips) are corrected to 5YR 8/4 and 5YR 3/2 as in the draft.
How the colors are computed
Each notation is defined by the Munsell renotation data of 1943, values set by a large visual experiment and published by the Munsell Color Science Laboratory at RIT. This page takes those values, adapts them from illuminant C to the D65 white of screens and converts them to sRGB with the colour-science library. A second, independent calculation (the R package aqp) agrees within ΔE 1 for 92% of the colored chips, under the common rule of thumb for the smallest difference people notice side by side, and the grays follow the ASTM D1535 lightness scale.
Other color tools
For soil notations such as 10YR 3/2 see the Munsell soil color chart; for every screen format of a color, the color converter.
Rock colors: questions
- What is the HEX code of a rock color?
- Type the notation into the converter at the top or find it in the chart below: 5YR 4/1 brownish gray is about #6A5E58 and 10YR 6/6 dark yellowish orange about #B68C50 on a standard sRGB screen. The values are computed from the Munsell renotation data, so they are screen approximations rather than the printed chips.
- How do I read a rock color notation like 5YR 4/1?
- It is a Munsell notation: 5YR is the hue (yellow-red), 4 the value (lightness from 0 for black to 10 for white) and 1 the chroma (strength of color). N followed by a number, such as N7, is a neutral gray of that lightness. Field descriptions usually give both the name and the notation, for example «brownish gray (5YR 4/1)».
- Should I describe a rock wet or dry?
- Either, but say which. According to the chart, wetting a rock mostly lowers the value, so the rock looks darker, while the chroma stays about the same; the chart includes dark chips so that wet specimens can be matched too.
- Why does the screen color not match my chart?
- The chart has painted chips viewed in daylight; a screen emits light and every monitor shows the same HEX a little differently. Use this page to read, record and compare notations, not to determine the color of a specimen. For a description, compare the rock with the physical chips.
- Is the Rock-Color Chart the same as the Munsell soil chart?
- No. Both use Munsell notation, but the rock chart has 115 chips spread across all hues, from red to purple, chosen from studies of rock specimens, while the soil book has full pages of the yellow-red hues common in soils. For soil notations see the Munsell soil color chart.
Sources
- Munsell Color (2009). Geological Rock-Color Chart, revision of the GSA Rock-Color Chart (copy in the INGEMMET library). Link
- Rock-Color Chart Committee, U.S. Geological Survey (1947). Preliminary draft of the rock-color chart (Internet Archive). Link
- Newhall S. M., Nickerson D., Judd D. B. (1943). Final report of the O.S.A. subcommittee on the spacing of the Munsell colors. Journal of the Optical Society of America 33(7), 385–418. DOI
- Munsell Color Science Laboratory, Rochester Institute of Technology: Munsell renotation data. Link
- Colour: open-source colour science library for Python (BSD-3). Link