Formula: Level 4 to 5, Chestnut to Light Brown, Gray Covered

Steps

Patch test 48 hours ahead, then estimate the white by eye on a clean, dry part line, at the front and again at the crown. Most colorists eyeball it, and if you want a number, count ten strands at the hairline.

Read the level at the root in daylight and take the hair history. Plainly brown in every light with warmth at the ends is a 4, and this formula assumes it has never been colored.

Mix 45 g 5N with 15 g 5.3 and 60 g of 20 vol, equal parts color to developer, fresh, in a plastic bowl. Under 25 percent white the 5N drops toward a quarter of the bowl. Above 75 it is the whole bowl, 5NN if the white is glassy.

Start where the white is. Front hairline and part line first, roots only, in thin sections with every white strand saturated top and underneath. Then mid-lengths and ends, then the roots through the back last, since the scalp is warm and they lift fastest.

Set one timer when the last section is on and cap the head. From 30, wipe a hairline strand clean and look at it dry. Translucent white means more time, up to 45. Covered means rinse at 35.

Rinse until the water runs clear, shampoo once with a color-safe shampoo, condition, and dry it. Check the hairline dry at the window before she leaves, because wet it reads a level darker and looks covered.

From the chair

The front takes the longest and it is what she sees in the mirror, so it gets the product first and the last look before the rinse.
Stubborn, glassy white: give it 45 minutes and use 5NN. Some colorists pre-soften the hairline with the mixed formula for five to ten minutes first, but time and a double natural do the same job on most heads.
If she wants it cooler, a little 5.1 (5A) can go in with the 5N. The pro lines mix ash into their naturals on purpose. What goes green is ash on its own over white, with no natural in the bowl to hold it.

Start at the front. On a head with white at the hairline, the front is what she sees in the mirror, and it is the hair that takes the longest to cover, so it gets the color first and the last look before the rinse. The pigmented hair through the back will lift on schedule whatever order you paint it in, and the white will not lift at all, so the only thing the order can cost you is coverage at the front.

What a natural 4 with white does under 20 vol

Two different hairs are on this head. The pigmented hair is a natural level 4, medium brown, and one level of lift from it brings up the red-orange underneath, which the natural and gold families sit on comfortably. The white has no pigment to lift and a cuticle that does not want to open, so the 20 vol (6 percent) only opens it for the deposit and the 5 goes on at full depth. Ten vol would blend that white, and 20 covers it, which is why 20 vol is the gray developer on every line. On a level 5 both hairs end up close together.

How much natural, and the ash question

Coverage is built from the natural series. A fashion shade alone on white gives shine with nothing under it, so a 5.3 by itself holds to about 25 percent white and goes see-through past that. The share of 5N follows the percentage, and our ladder is a safe starting point that leans heavy on purpose, because a see-through hairline at the second shampoo brings her back.

White at the front	Natural share (ours)	In 60 g at level 5	Wella’s guidance
Up to 25 percent	1/4 N	15 g 5N + 45 g 5.3	Target shade alone under 30
30 to 50 percent	1/2 N	30 g 5N + 30 g 5.3	A third natural
55 to 75 percent	3/4 N	45 g 5N + 15 g 5.3	Half natural
80 to 100 percent	All N, 5NN if resistant	60 g 5N, gold as a demi toner after	Half natural and half target

A 35 percent hairline gets three quarters 5N in my bowl, above both columns. The gray coverage calculator does the grams from whichever column you trust.

If she wants it cooler, a little 5.1 (a 5A on letter lines) can go in with the 5N. The pro lines mix ash into their naturals on purpose, and an ash shade with a natural base under it covers fine. The thing that goes green and dull at the hairline is ash on its own over white, with no natural in the bowl to hold it. Ash also reads darker, so tell her the cool version will look a touch deeper than the warm one.

The order, and 35 minutes

Sixty grams of color to sixty of 20 vol, equal parts, an ounce and an ounce if you measure that way, mixed fresh in a plastic bowl and used now. Dry hair, thin sections, saturation on every white strand top and underneath, because a white hair that got a thin coat stays white. Front hairline and part line first, roots only. Then mid-lengths and ends. Then the roots through the back last, since the scalp is warm and pigmented roots lift fastest. If you use barrier cream, keep it off the white baby hairs at the hairline, or the color will not get through.

One timer when the last section is on, and a cap over it to hold the scalp warmth. From 30 wipe a hairline strand clean and look at it. Translucent means the white needs more time, five minutes at a stretch to 45. Opaque means rinse at 35. Read the directions on your line too, since every line sets its own time for gray, and more is not more once the white is covered.

If the lengths have ever been colored Permanent color lifts natural pigment only. A box 4 through the lengths stays a 4 while the regrowth lifts to a 5. A color remover first takes out the old dye and leaves the natural alone, then read the level again, or accept the band and put a demi through the lengths.

The retouch, and the other road

The white shows first, at the front, at about four weeks. The level line, a 4 under a 5, is soft enough that most people see the white before it. Book her at five. The retouch is the same bowl on the regrowth only, 20 vol, 35 minutes, hairline first again, with a demi 5N and a little 5.3 on 10 vol through the lengths for the last five minutes. Do not run the permanent through the lengths every visit. They are colored now, and if she ever asks for lighter than a 5 they will need a remover or a lightener while the regrowth alone takes the 4 to 6 formula.

And if the line at four weeks bothers her more than the white did, the other road is a blend: a demi at her level on 10 vol, or lowlights through the white, which takes the edge off the gray without covering it and grows out soft over eight to ten weeks. Solid permanent coverage is the right service for a client who wants the white gone. It is the wrong one for a client who only wanted it quieter.

Asked about the white

Can I cover gray and go lighter at the same time?

One level, yes, on 20 vol. It lifts the pigmented hair a level and deposits on the white in the same 35 minutes. Two levels on 30 vol gives sheerer coverage, and three is two appointments. Most colorists stay within a level or two of the natural when there is white to cover, and this stays within one.

Why is most of the bowl 5N when she wanted warm?

Because the natural series does the covering. A 5.3 on its own holds white to about 25 percent and goes see-through past that. The quarter of 5.3 is there so the covered white does not read flat next to the warm lift on the rest.

How do I know the percentage?

By eye, mostly. Look at a clean dry part line at the front and at the crown separately and call it in tens. If you want to be exact, count ten strands at the hairline. The gray coverage calculator turns the number into grams.

Will the lift show on the white hair?

No. White hair has nothing to lift, so the 20 vol only opens it for the deposit, and the 5 goes on at the depth on the tube. The lift happens on the pigmented hair around it.

How is this different from the 4 to 6 formula?

Two levels versus one, and what that costs the coverage. Going to a 6 from a 4 is still 20 vol but at the top of what it does, with softer coverage on the white. This one has room to spare and covers fully, and level 5 is where it stops.