About

Print-based color workflows operate in the CMYK subtractive model. Screen-based workflows use additive RGB. A mismatch between the two causes color drift visible on proof prints, packaging mock-ups, and brand collateral. This tool converts arbitrary C, M, Y, K channel values (each 0 - 100) into their RGB, HEX, HSL, and HSV equivalents. It then performs a nearest-neighbor search in Euclidean RGB space against a dictionary of named Colortones and a subset of Pantone Solid Coated references, returning the closest match and a ΔE distance score. Note: the CMYK-to-RGB conversion used here is the standard idealized formula and does not incorporate ICC color profiles. Real-world print output varies with ink density, paper stock, and press calibration.

Formulas

The standard idealized CMYK-to-RGB conversion treats each channel as a percentage absorption factor. With no ICC profile, the formula assumes pure ink behavior:

R = 255 × (1 − C100) × (1 − K100)

G = 255 × (1 − M100) × (1 − K100)

B = 255 × (1 − Y100) × (1 − K100)

Colortone matching uses Euclidean distance in RGB space:

Δ = √(R₁ − R₂)² + (G₁ − G₂)² + (B₁ − B₂)²

Where C = Cyan (0 - 100), M = Magenta (0 - 100), Y = Yellow (0 - 100), K = Key/Black (0 - 100). R, G, B are integer channel values in the range 0 - 255. Δ is the Euclidean distance. Lower values indicate a closer match. A Δ < 15 is generally imperceptible to the human eye.

Reference Data

Colortone Name	CMYK (C/M/Y/K)	HEX	RGB	Category
Pure Black	0/0/0/100	#000000	0, 0, 0	Neutral
Rich Black	60/40/40/100	#000000	0, 0, 0	Neutral
Cool Gray	0/0/0/40	#999999	153, 153, 153	Neutral
Warm Gray	0/5/10/30	#B3A99A	179, 169, 154	Neutral
Pure White	0/0/0/0	#FFFFFF	255, 255, 255	Neutral
Signal Red	0/100/100/0	#FF0000	255, 0, 0	Red
Crimson	0/90/80/20	#CC1429	204, 20, 41	Red
Coral	0/50/50/0	#FF8080	255, 128, 128	Red
Salmon	0/40/40/0	#FF9999	255, 153, 153	Red
Rose	0/60/20/0	#FF66CC	255, 102, 204	Pink
Magenta	0/100/0/0	#FF00FF	255, 0, 255	Pink
Fuchsia	10/90/0/0	#E61AFF	230, 26, 255	Pink
Blush	0/25/15/0	#FFBFD9	255, 191, 217	Pink
Orange	0/50/100/0	#FF8000	255, 128, 0	Orange
Tangerine	0/60/100/0	#FF6600	255, 102, 0	Orange
Peach	0/20/40/0	#FFCC99	255, 204, 153	Orange
Amber	0/30/90/0	#FFB31A	255, 179, 26	Yellow
Canary Yellow	0/0/100/0	#FFFF00	255, 255, 0	Yellow
Gold	0/10/80/10	#E6CF2E	230, 207, 46	Yellow
Lemon	5/0/70/0	#F2FF4D	242, 255, 77	Yellow
Cream	0/5/20/0	#FFF2CC	255, 242, 204	Yellow
Forest Green	80/0/80/40	#1F991F	31, 153, 31	Green
Lime	30/0/100/0	#B3FF00	179, 255, 0	Green
Mint	30/0/20/0	#B3FFCC	179, 255, 204	Green
Emerald	80/0/60/20	#29CC52	41, 204, 82	Green
Olive	20/0/80/40	#7A991F	122, 153, 31	Green
Teal	80/0/20/20	#29CCA3	41, 204, 163	Cyan
Cyan	100/0/0/0	#00FFFF	0, 255, 255	Cyan
Aqua	50/0/10/0	#80FFE6	128, 255, 230	Cyan
Sky Blue	40/10/0/0	#99E6FF	153, 230, 255	Blue
Royal Blue	80/60/0/0	#336699	51, 102, 255	Blue
Navy	100/80/0/40	#001F99	0, 31, 153	Blue
Cobalt	90/60/0/10	#175CE6	23, 92, 230	Blue
Cerulean	70/20/0/0	#4DCCFF	77, 204, 255	Blue
Indigo	60/80/0/20	#522ECC	82, 41, 204	Violet
Violet	40/80/0/0	#9933FF	153, 51, 255	Violet
Plum	30/70/0/30	#7A3636	125, 54, 179	Violet
Lavender	20/30/0/0	#CCB3FF	204, 179, 255	Violet
Mauve	10/40/0/10	#CF8AE6	207, 138, 230	Violet
Burgundy	20/90/80/40	#7A0F1F	122, 15, 31	Brown
Chocolate	20/60/80/40	#7A3D1F	122, 61, 31	Brown
Sienna	10/50/70/30	#A15936	161, 89, 54	Brown
Tan	0/15/30/10	#E6C4A1	230, 196, 161	Brown
Ivory	0/2/10/0	#FFFBE6	255, 250, 230	Neutral
Slate	30/10/0/50	#597380	89, 115, 128	Neutral
Charcoal	0/0/0/80	#333333	51, 51, 51	Neutral

Frequently Asked Questions

This converter uses the idealized CMYK-to-RGB formula without an ICC color profile. Real printers apply device-specific profiles that account for ink absorption, paper reflectance, and dot gain. The converted RGB value is a mathematical approximation. For print-critical work, use a calibrated color management workflow with profiles specific to your press and substrate.

The distance score (Δ) is the Euclidean distance between your input color's RGB values and the nearest named Colortone in the reference dictionary. A Δ below 15 is generally indistinguishable to the human eye. A Δ between 15 and 40 indicates a close but noticeable difference. Above 40, the match is approximate at best. The score helps you judge whether the named Colortone is a reliable label for your color.

The K channel acts as a global darkening multiplier. Setting K to 100 forces R, G, and B to 0 regardless of C, M, or Y values. In print, K replaces the theoretical 100/100/100 CMY mix (which produces a muddy dark brown, not true black). The formula multiplies each channel by (1 − K/100), so even moderate K values significantly reduce lightness. A CMYK value of 0/0/0/50 yields a neutral mid-gray (RGB 128/128/128).

The tool provides an approximate Pantone Solid Coated match using nearest-neighbor search across a subset of ~60 commonly used Pantone references. This is not a licensed Pantone lookup. For contractual or brand-critical color matching, always verify against a physical Pantone swatch book. The tool's Pantone approximation is useful for initial exploration, not final specification.

The CMYK-to-RGB conversion is a many-to-one mapping. Multiple CMYK combinations can produce identical RGB output because the K channel absorbs light that could also be absorbed by combining C, M, and Y. For example, CMYK 0/0/0/100 and CMYK 100/100/100/0 both map to near-black. Additionally, rounding to integer RGB values collapses nearby floating-point results into the same 8-bit triplet.

Not for the mathematical conversion itself, which is deterministic. However, ambient lighting conditions (color temperature of your room light, screen brightness, blue light filters) significantly affect how your eyes perceive the on-screen swatch. For accurate visual assessment, view the swatch on a calibrated monitor (D65 white point, 120 cd/m² luminance) in a controlled lighting environment around 5000K.