How to Cover Gray Hair with Igora Royal: The Exact Ratio

Level 6 base, plenty of gray already showing, and the Igora Royal shade in your hand isn’t one that covers on its own. How much natural goes in the bowl?

If you formulate with Igora Royal every week, Schwarzkopf’s US wall chart answers it in one line, with a gram example and a list of the shades that don’t need it.

Here’s what the chart says: the ratio, the grams, the change on thick hair, and which shades fall outside the rule.

How much natural does a partial-coverage Igora Royal shade need?

On hair with more than 50% gray, the US wall chart adds 1 part of a Natural (-0) or Beige (-4) shade to a partial-coverage shade in a 2:1 ratio. On thick, resistant hair, it mixes shade and natural in equal parts. The chart’s example: 40g of 6-65 + 20g of 6-4 + 60g of developer.

The chart states it as a condition: “When shades with up to 70% coverage are used on more than 50% white hair, add 1 part of a Natural (-0) or Beige (-4) series in a 2:1 ratio to achieve 100% coverage. Mix 1:1 for thick and resistant hair.” It’s the IGORA Color System wall chart, Schwarzkopf Professional’s US edition.

If you also read the chart’s Spanish side, note that it translates “up to 70% coverage” as “coverage above 70%”, the opposite meaning. Follow the English. If your salon works from a Schwarzkopf chart printed for another market, the UK included, check its cutoff before you apply this one.

Which shades fall outside this rule

The ratio above doesn’t apply to the whole range. The US chart splits it like this:

Group	What the chart says	Needs a natural shade
100% coverage shades: series -00, -0, -1, -4, -63	Listed among the chart’s 100% coverage shades	No
IGORA ROYAL Absolutes	Up to 100% coverage on more than 50% gray, “without having to mix with a natural tone”	No
Partial-coverage shades	”Shades with up to 70% coverage”	Yes, above 50% gray: 2:1, or equal parts on thick, resistant hair

The 100% coverage list gives code endings, not levels or series, so a code ending in -0 or -1 isn’t enough on its own. The Ultra Blonde (10-) and Special Blonde (12-) series have their own block in the chart (IGORA ROYAL Highlifts, mixed 1:1 and 1:2) and show up in the developer guide only under lifting; Fashion Lights has its own mixing row and goes in the 12% column. The natural rule doesn’t mention any of them, so don’t read a 10- or 12- shade as a coverage shade because of how its code ends. Absolutes is its own range, and choosing a shade from it depends on the tone and the level you need: the Absolutes guide maps both.

This split between series is specific to Igora Royal. Other lines solve the same question differently: Wella sets its own brackets by gray percentage in Koleston Perfect, and L’Oréal splits its Majirel instruction at 50% white depending on whether the target shade is warm or cool. The general gray hair coverage guide brings the charts together in one table if you work across brands.

The gram example, step by step

The US chart doesn’t stop at the ratio: it prints an example with quantities. On a 6-65 (level 6, Dark Blonde, with Chocolate as the main tone and Gold as the secondary), with more than 50% gray on hair that isn’t thick or resistant:

• 40g of 6-65 (the chosen shade)
• 20g of 6-4 (the Beige of the same level the chart uses in its example)
• 60g of developer

The 40g and 20g keep the 2:1 ratio, and the 60g of developer matches the 60g of color cream, shade and Beige together. With another partial-coverage shade, the same logic applies with a Natural (-0) or a Beige (-4); in its example, the chart takes it from the same level as the shade. The chart’s mixing ratio for Igora Royal is 1:1 with IGORA ROYAL Oil Developer, with a development time of 30 to 45 minutes.

The example doesn’t print a developer strength, and the chart doesn’t tie one to this mix. Read its developer guide by what the formula has to do: the 3% (10 vol) column lists coloring darker hair and covering 100% white hair; the 6% (20 vol) column lists tone-on-tone coloration, coverage on white hair and lifting 1 to 2 levels.

Weigh it, don’t eyeball it.

Pro tip: the chart’s only example pairs a 6-65 (Chocolate, Gold) with the Beige of the same level, 6-4. It doesn’t rule on -0 versus -4 for other shades, so write on the client card which one went in and the grams of each. That’s how you repeat a result that worked.

What changes on thick, resistant hair

On thick, resistant hair, the US chart drops the ratio to equal parts: “Mix 1:1 for thick and resistant hair.” It doesn’t print an example for this case. Keeping the same 60g of color cream, that works out to 30g of 6-65 + 30g of 6-4 with 60g of developer.

The chart doesn’t explain why. Read in context, that 1:1 is shade to natural: it replaces the 2:1 in the same sentence. The chart’s mixing table keeps Igora Royal at 1:1 color cream to developer, with no separate line for thick hair.

Root by root, section by section.

Before you mix

Among its helpful hints, the US chart lists its own application warnings: “Do not apply product on damaged or irritated scalp and avoid pre-shampooing”, “Refrain from any kind of head massage shortly before or during the entire coloring procedure”, “Observe accurate development time and ensure complete rinsing of color mixture after development”, and “Do not use heat.” Heat isn’t a shortcut for resistant gray with this line. Write the gray percentage on the client card as a number: it’s what decides whether the natural goes in at all.

Before any color service, run the skin allergy test described in the product’s instructions. The first time you use the equal-parts mix on a client, test it on a strand first.

Common mistakes when formulating with this rule

1. Applying the 2:1 ratio to a 100% coverage shade. If the shade belongs to one of the series the chart lists as 100% coverage, or to Absolutes, the chart doesn’t call for adding natural.
2. Defaulting to 2:1 on thick hair. The chart calls for equal parts of shade and natural in that case; keeping 2:1 departs from its instruction on exactly the hair that’s hardest to cover.
3. Putting resistant gray under heat to push coverage. The chart says “Do not use heat” for this line. Thick, resistant hair gets more natural in the bowl, not a processor.

Frequently asked questions

Which Igora Royal shades don’t need natural to cover gray?

On the US wall chart, the series -00, -0, -1, -4 and -63, which it lists as 100% coverage shades, plus the Absolutes range, which covers up to 100% “without having to mix with a natural tone”.

How much natural goes into a partial-coverage Igora Royal shade?

Above 50% gray, the US chart adds a Natural (-0) or Beige (-4) to the shade in a 2:1 ratio. It illustrates it with 40g of shade + 20g of Beige + 60g of developer.

Does the ratio change depending on hair type?

Yes. On thick, resistant hair, the US chart mixes shade and natural in equal parts instead of 2:1.

What developer goes with this mix?

The chart’s example prints 60g of developer without a strength. Its developer guide puts covering 100% white hair under 3% (10 vol), next to coloring darker, and coverage on white hair under 6% (20 vol), next to tone-on-tone and 1 to 2 levels of lift. Pick the column by what the formula has to do.

In summary

• The rule: above 50% gray, a partial-coverage shade takes a Natural (-0) or Beige (-4) in a 2:1 ratio (US chart).
• Thick, resistant hair: shade and natural in equal parts.
• No natural needed: the 100% coverage series (-00, -0, -1, -4, -63) and Absolutes.

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