Color Conversion

Colorium provides seamless conversion between all supported color spaces. This guide covers every conversion method available.

Overview of Color Spaces

Colorium supports conversion between these color spaces:

FromToMethod
AnyRGBto_rgb()
AnyHSLto_hsl()
AnyHWBto_hwb()
AnyCMYKto_cmyk()
AnyOKLCHto_oklch()
AnyLABto_lab()
AnyLCHto_lch()
AnyP3to_p3()

String Conversions

Basic String Formats

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from colorium import Color

color = Color(255, 0, 0)

# RGB string
print(color.to_rgb_string())    # rgb(255, 0, 0)
print(color.to_rgba_string())   # rgba(255, 0, 0, 1.00)

# HSL string
print(color.to_hsl_string())    # hsl(0, 100%, 50%)
print(color.to_hsla_string())   # hsla(0, 100%, 50%, 1.00)

# HWB string
print(color.to_hwb_string())    # hwb(0, 0%, 0%)
print(color.to_hwba_string())   # hwba(0, 0%, 0%, 1.00)

# CMYK string
print(color.to_cmyk_string())   # cmyk(0%, 100%, 100%, 0%)

# Hex string
print(color.to_hex_string())    # #FF0000

Modern CSS Color Level 4 Strings

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from colorium import Color

color = Color(255, 0, 0)

# OKLCH string
print(color.to_oklch_string())  # oklch(62.8% 0.258 29.2)

# LAB string
print(color.to_lab_string())    # lab(53.2% 80.1 67.2)

# LCH string
print(color.to_lch_string())    # lch(53.2% 104.5 40.0)

# P3 string
print(color.to_p3_string())     # color(display-p3 0.823 0.033 0.017)

NCOL String

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from colorium import Color

color = Color(255, 0, 0)
print(color.to_ncol_string())   # ncol(R0, 0%, 0%)

Dictionary Conversions

RGB Dictionary

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from colorium import Color

color = Color(100, 150, 200)
rgb = color.to_rgb()

print(rgb['r'])  # 100
print(rgb['g'])  # 150
print(rgb['b'])  # 200
print(rgb['a'])  # 1.0

HSL Dictionary

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from colorium import Color

color = Color(255, 0, 0)
hsl = color.to_hsl()

print(hsl['h'])  # 0
print(hsl['s'])  # 1.0
print(hsl['l'])  # 0.5
print(hsl['a'])  # 1.0

HWB Dictionary

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from colorium import Color

color = Color(100, 150, 200)
hwb = color.to_hwb()

print(hwb['h'])  # Hue (0-360)
print(hwb['w'])  # Whiteness (0-1)
print(hwb['b'])  # Blackness (0-1)
print(hwb['a'])  # Opacity (0-1)

CMYK Dictionary

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from colorium import Color

color = Color(100, 150, 200)
cmyk = color.to_cmyk()

print(cmyk['c'])  # 0.5
print(cmyk['m'])  # 0.25
print(cmyk['y'])  # 0.0
print(cmyk['k'])  # 0.22
print(cmyk['a'])  # 1.0

OKLCH Dictionary

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from colorium import Color

color = Color(100, 150, 200)
oklch = color.to_oklch()

print(oklch['l'])  # Lightness (0-1)
print(oklch['c'])  # Chroma (0-0.4+)
print(oklch['h'])  # Hue (0-360)

LAB Dictionary

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from colorium import Color

color = Color(100, 150, 200)
lab = color.to_lab()

print(lab['l'])  # Lightness (0-100)
print(lab['a'])  # a* (-128 to 128)
print(lab['b'])  # b* (-128 to 128)

LCH Dictionary

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from colorium import Color

color = Color(100, 150, 200)
lch = color.to_lch()

print(lch['l'])  # Lightness (0-100)
print(lch['c'])  # Chroma (0-100+)
print(lch['h'])  # Hue (0-360)

P3 Dictionary

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from colorium import Color

color = Color(100, 150, 200)
p3 = color.to_p3()

print(p3['r'])  # Red (0-1)
print(p3['g'])  # Green (0-1)
print(p3['b'])  # Blue (0-1)

Converting Between Spaces

Direct Conversion Methods

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from colorium import Color

color = Color(255, 0, 0)

# To RGB
rgb = color.to_rgb()

# To HSL
hsl = color.to_hsl()

# To HWB
hwb = color.to_hwb()

# To CMYK
cmyk = color.to_cmyk()

# To OKLCH
oklch = color.to_oklch()

# To LAB
lab = color.to_lab()

# To LCH
lch = color.to_lch()

# To P3
p3 = color.to_p3()

Creating from Different Spaces

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from colorium import from_hsl, from_hwb, from_cmyk
from colorium import from_oklch, from_lab, from_lch, from_p3

# From HSL
hsl_color = from_hsl(200, 0.8, 0.5)

# From HWB
hwb_color = from_hwb(180, 0.2, 0.1)

# From CMYK
cmyk_color = from_cmyk(0.2, 0.8, 0.1, 0.3)

# From OKLCH
oklch_color = from_oklch(0.5, 0.2, 180)

# From LAB
lab_color = from_lab(50, 20, -30)

# From LCH
lch_color = from_lch(50, 30, 180)

# From P3
p3_color = from_p3(0.8, 0.3, 0.5)

Round-Trip Conversion

Colorium ensures accurate round-trip conversions.

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from colorium import Color, from_hsl

# Create a color
original = Color(100, 150, 200)

# Convert to HSL and back
hsl = original.to_hsl()
recreated = from_hsl(hsl['h'], hsl['s'], hsl['l'])

# Check accuracy
print(f"Original: {original.to_hex_string()}")
print(f"Recreated: {recreated.to_hex_string()}")
print(f"Match: {original == recreated}")  # True

Conversion Accuracy

Precision

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from colorium import Color

color = Color(100, 150, 200)

# Values are rounded to reasonable precision
hsl = color.to_hsl()
print(hsl['s'])  # 0.48 (rounded to 2 decimals)

oklch = color.to_oklch()
print(oklch['l'])  # 0.567 (rounded to 3 decimals)

Tolerance

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from colorium import Color

# Small differences are expected due to rounding
color1 = Color(100, 150, 200)
color2 = Color(101, 149, 201)

# Use tolerance for comparison
def colors_close(c1, c2, tolerance=2):
    return (
        abs(c1.red - c2.red) <= tolerance and
        abs(c1.green - c2.green) <= tolerance and
        abs(c1.blue - c2.blue) <= tolerance
    )

print(colors_close(color1, color2))  # True

Conversion Performance

Caching

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from colorium import Color

color = Color(100, 150, 200)

# Good - values are cached internally
hsl1 = color.to_hsl()
hsl2 = color.to_hsl()  # Fast - uses cache

# Bad - unnecessary conversion
rgb1 = color.to_rgb()
rgb2 = color.to_rgb()  # Still fast due to cache

Batch Conversion

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from colorium import Color

def batch_convert_to_hsl(colors):
    """Convert multiple colors to HSL"""
    return [color.to_hsl() for color in colors]

colors = [
    Color(100, 150, 200),
    Color(255, 0, 0),
    Color(0, 255, 0)
]

hsl_values = batch_convert_to_hsl(colors)
for hsl in hsl_values:
    print(f"H: {hsl['h']}, S: {hsl['s']}, L: {hsl['l']}")

Common Conversion Patterns

RGB to Hex

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from colorium import Color

color = Color(255, 0, 0)
hex_string = color.to_hex_string()
print(hex_string)  # #FF0000

Hex to RGB

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from colorium import from_hex

color = from_hex("#FF0000")
print(color.to_rgb())  # {'r': 255, 'g': 0, 'b': 0}

HSL to RGB

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from colorium import from_hsl

color = from_hsl(200, 0.8, 0.5)
rgb = color.to_rgb()
print(rgb)  # {'r': 50, 'g': 150, 'b': 200}

RGB to CMYK

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from colorium import Color

color = Color(255, 0, 0)
cmyk = color.to_cmyk()
print(cmyk)  # {'c': 0.0, 'm': 1.0, 'y': 1.0, 'k': 0.0}

LAB to RGB

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from colorium import from_lab

color = from_lab(50, 20, -30)
rgb = color.to_rgb()
print(rgb)  # {'r': 100, 'g': 150, 'b': 200}

Conversion Reference Table

MethodReturnsFormat
to_rgb()Dict{'r': 0-255, 'g': 0-255, 'b': 0-255, 'a': 0-1}
to_hsl()Dict{'h': 0-360, 's': 0-1, 'l': 0-1, 'a': 0-1}
to_hwb()Dict{'h': 0-360, 'w': 0-1, 'b': 0-1, 'a': 0-1}
to_cmyk()Dict{'c': 0-1, 'm': 0-1, 'y': 0-1, 'k': 0-1, 'a': 0-1}
to_oklch()Dict{'l': 0-1, 'c': 0-0.4+, 'h': 0-360}
to_lab()Dict{'l': 0-100, 'a': -128-128, 'b': -128-128}
to_lch()Dict{'l': 0-100, 'c': 0-100+, 'h': 0-360}
to_p3()Dict{'r': 0-1, 'g': 0-1, 'b': 0-1}

Next Steps

Previous: Color Manipulation Next: Color Filters →

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