Color Mixing

Part of Natural Dyes & Inks

Combining natural dye colors through over-dyeing, blending baths, and fiber mixing.

Why This Matters

The natural dye palette from single sources is limited — yellows, reds, blues, and browns cover most of what individual plants produce. But the colors of a functioning textile culture extend far beyond these basics. Greens, purples, oranges, teals, olive, rust, burgundy, and dozens of intermediate shades are all achievable through the systematic mixing of primary dye colors.

Understanding color mixing with natural dyes is different from mixing paint. In paint, you physically blend pigments. In natural dyeing, you achieve mixed colors primarily through over-dyeing — applying one color on top of another in sequence. The results follow subtractive color theory (like paint) but the methods are additive and sequential. Getting predictable results requires understanding which dyes layer well, in what order to apply them, and how mordants and modifiers shift the final color.

This knowledge transforms a limited palette of 4-5 base colors into a virtually unlimited spectrum, all from locally available plant materials.

Color Theory for Natural Dyes

The Three Primaries

Natural dye primaries correspond roughly to the artist’s subtractive primaries:

Primary	Best Sources	Dye Type
Yellow	Weld, onion skins, goldenrod, marigold	Mordant dye (alum)
Red	Madder, cochineal, brazilwood	Mordant dye (alum)
Blue	Indigo, woad	Vat dye (no mordant needed)

Mixing Table

Combine	To Get	Notes
Yellow + Blue	Green	Most reliable mixed color
Red + Blue	Purple	Requires strong red base
Red + Yellow	Orange	Easy and predictable
Yellow + Brown	Olive	Common natural combination
Red + Brown	Rust / Burgundy	Depends on brown type
Blue + Brown	Dark teal	Unusual but effective
Any color + Iron	Darker, greyed version	Universal darkening agent

Over-Dyeing Technique

Over-dyeing means dyeing a fiber that has already been dyed a different color. The two colors combine in the fiber to produce a third color.

General Principles

1. Dye order matters — Generally dye the lighter color first, then the darker. Blue over yellow is easier to control than yellow over blue.

2. Indigo goes last (usually) — Because indigo is a vat dye that doesn’t require mordant, it can be applied to already-mordanted and dyed fibers without disturbing the first color. This makes it the ideal “second dye.”

3. Mordant dyes can go in any order — If both colors are mordant dyes (e.g., yellow weld + red madder for orange), the order is less critical. The first dye may be partially displaced by the second, so start with the weaker color.

4. Test first — Natural dyes vary enormously based on source, mordant, water chemistry, and technique. Always test on a small sample before committing valuable fiber.

5. Record everything — Keep notes on every color you achieve: dye source, mordant, dip time, temperature, fiber type, and order of over-dyeing. Natural dyeing is empirical — your records are your recipe book.

Step-by-Step Over-Dyeing

To produce green (yellow + blue):

1. Mordant the fiber with alum (10-15% WOG for wool)
2. Dye yellow first — Simmer mordanted fiber in weld or other yellow dye bath for 45-60 minutes
3. Rinse gently — Remove excess dye but don’t scrub
4. Dry — Optional but allows you to evaluate the yellow before proceeding
5. Dye blue — Dip the yellow-dyed fiber in a prepared indigo vat. Follow standard indigo vat procedure.
6. Oxidize — Remove from vat and allow to oxidize in air for 15-20 minutes
7. Evaluate — The combination of yellow base + blue overlay produces green. For deeper green, additional indigo dips are needed. For a more yellow-green, use a strong yellow base and fewer blue dips.

Mixing Methods

Method 1: Sequential Over-Dyeing (Most Common)

Dye the fiber in one color, rinse, then dye in the second color.

Advantages:

• Maximum control over each component color
• Can evaluate at each stage
• Can adjust the second color based on how the first turned out

Disadvantages:

• More handling (risk of felting wool)
• Takes longer
• Each dye bath must be prepared separately

Method 2: Combined Dye Bath

Mix two or more dye extracts in a single bath and dye fiber in the combined solution.

Advantages:

• Faster — single step
• More even color (both dyes absorbed simultaneously)
• Less handling

Disadvantages:

• Less control — can’t adjust individual components mid-process
• Some dyes interfere with each other in the same bath
• pH requirements may conflict (indigo cannot be combined this way — it requires its own alkaline, reducing vat)

Works well for:

• Combining two mordant dyes (e.g., madder + weld for orange)
• Combining a mordant dye with a tannin dye
• Creating complex browns and earth tones

Does not work for:

• Any combination involving indigo (must be a separate vat)
• Dyes with incompatible pH requirements

Method 3: Fiber Blending

Dye individual batches of fiber different colors, then spin or weave them together. The eye mixes the colors optically.

Advantages:

• No chemical interaction between dyes
• Produces heathered, complex textures
• Broken color effect can be more visually interesting than solid mixed color

Disadvantages:

• Requires more planning and separate dye baths
• Not a true mix — individual colors visible up close
• More labor (dyeing multiple batches, then blending)

Applications:

• Spinning two colors of dyed wool together (marled yarn)
• Weaving with different colored warp and weft (shot fabric)
• Plying differently-dyed yarns together

Achieving Specific Colors

Greens

Green is the most commonly sought mixed color and the most reliable to achieve.

Green Shade	Yellow Source	Blue Source	Modifier
Bright grass green	Weld (strong)	Indigo (1-2 dips)	None
Forest green	Weld (moderate)	Indigo (3-4 dips)	None
Olive green	Weld or onion skin	Indigo (light)	Iron after-bath
Sage green	Chamomile	Indigo (1 dip)	None
Teal	Osage orange (strong yellow)	Indigo (2-3 dips)	None
Khaki green	Goldenrod	—	Iron after-bath

Purples

Purple is challenging because it requires a strong, clear red base and a controlled blue overlay.

Purple Shade	Red Source	Blue Source	Notes
Violet	Madder (alum mordant)	Indigo (1-2 dips)	Use clear, bright madder red
Plum	Madder (strong)	Indigo (2-3 dips)	Rich and deep
Lavender	Madder (light)	Indigo (1 dip)	Delicate — hard to control
Magenta-purple	Cochineal	Indigo (1 dip)	Vivid if cochineal available
Aubergine	Madder + tannin	Indigo (3+ dips)	Dark and rich

Oranges

Orange Shade	Method
Bright orange	Madder (alum mordant, pH slightly acidic) + weld over-dye
Burnt orange	Madder + onion skin combined bath
Peach	Light madder + light weld
Rust	Madder + iron after-bath
Coral	Cochineal (light) + weld (light)

Color Modifiers

Modifiers shift an existing color without adding a new dye. They work by changing the chemistry of the dye-mordant-fiber complex.

Iron (Saddening)

• Effect: Darkens and dulls colors; shifts toward grey, olive, and black
• Application: Dip dyed fiber in iron water (2-4% WOG iron sulfate, or rusty nail solution) for 10-30 minutes
• Yellow → olive/grey-green
• Red → brown/maroon
• Blue → dark blue/grey
• Use sparingly — excess iron damages fibers

Alkali (Brightening/Shifting)

• Effect: Shifts many dyes toward blue/purple end of spectrum; can brighten
• Application: Dip in wood ash water (lye) or add washing soda to rinse water
• Yellow → sometimes greenish
• Red → shifts toward purple
• Caution: Can strip dye from wool if too strong

Acid (Warming/Shifting)

• Effect: Shifts many dyes toward red/yellow end of spectrum
• Application: Add vinegar or sour fruit juice to rinse water
• Purple → shifts toward red
• Some yellows brighten
• Generally gentler than alkali modifications

Copper (Greening)

• Effect: Shifts colors toward green; brightens some yellows
• Application: Use copper sulfate (blue vitriol) at 2-3% WOG, or soak fiber in water that has sat in a copper vessel
• Yellow → warmer, greener yellow
• Brown → olive-brown
• Use less common due to copper toxicity

Practical Color Mixing Guide

Building a Complete Palette from Minimal Sources

With just four dye sources plus iron, you can produce a remarkably full palette:

Starting materials: Weld (yellow), Madder (red), Indigo (blue), Walnut hulls (brown), Iron scraps

Color	Method
Yellow	Weld + alum
Gold	Weld + alum (concentrated)
Orange	Weld + madder combined bath
Red	Madder + alum
Pink	Light madder + alum
Purple	Madder + indigo over-dye
Blue	Indigo vat
Green	Weld + indigo over-dye
Olive	Weld + iron
Brown	Walnut hulls (no mordant)
Dark brown	Walnut + iron
Grey	Light tannin + iron
Black	Heavy tannin + iron (multiple cycles)
Tan/Khaki	Light walnut or light weld + iron

Record-Keeping

Maintain a sample book — a collection of dyed fiber samples with complete notes:

Record Field	Why It Matters
Fiber type	Different fibers take dye differently
Mordant and percentage	Controls color intensity and hue
Dye source and quantity	Reproducibility
Dye bath temperature and time	Affects shade and depth
Over-dye sequence	Order matters for final color
Modifier used	Documents the shift achieved
Date	Track lightfastness over time

Attach a small sample of the dyed fiber next to each entry. Over time, this becomes an invaluable reference that eliminates guesswork and allows you to reproduce any color reliably.

Start Simple

Begin with two-color combinations before attempting three-color over-dyes. Master yellow + blue = green and red + yellow = orange before attempting the more complex purples and olives. Each additional color layer adds unpredictability.