Matching a RAL number at the paint counter

Most paint shops can mix a RAL Classic colour for you, and most of the time the result is good. The trouble starts when people walk in with only a number and a vague idea of what the paint is for. The person behind the counter then has to guess the product, the base and the finish, and every one of those guesses changes the colour you take home. This guide walks through what happens at the counter, step by step, and what to say at each point so the tin in your hand is the one you meant to buy.

How tinting works, in plain terms

A tinted paint starts life as an untinted base: a tin of paint that contains the binder, the white pigment (or less of it) and everything else except most of the colour. The shop's tinting machine then squirts measured amounts of concentrated colourants into that base, following a formula, and a shaker or mixer blends it.

The formula comes from a database supplied by the paint maker. For each product and each colour, the maker has worked out which base to use and how much of each colourant to add. When you ask for a RAL number, the shop looks up that number for that specific product. If the maker has not built a formula for that combination, the shop may offer the nearest one it has, or a formula from a different product line, and that is where surprises come from.

Three details matter here.

1. Bases come in strengths. Most ranges have something like a white or pastel base (lots of white pigment, for light colours), one or two medium bases, and a deep or clear base (little or no white, for strong and dark colours). A light grey goes in a pastel base. A dark green needs a deep base. The shop picks the base, but it helps to know this when a tin looks half-empty before tinting: a deep base is filled short on purpose to leave room for colourant.
2. Colourant sets are limited. A tinting machine holds a fixed set of colourants, often a dozen or so. Some very clean, strong colours are hard to reach with that set, so the formula gets as close as it can.
3. The formula is product-specific. The same RAL number in an interior emulsion and in an exterior metal paint uses different formulas, different bases and sometimes different colourants. Expect them to look close, not identical.

Step 1: say "RAL Classic" and the four digits

RAL has more than one colour collection. RAL Classic is the familiar one, with about two hundred colours numbered with four digits, such as RAL 7016. RAL Design is a separate system with much longer numbers, and RAL Effect is another separate range. If you say "RAL 9010" most staff will know what you mean, but saying "RAL Classic 9010" removes any doubt, and it matters more in shops whose database lists several systems side by side.

Write it down too. Spoken numbers get misheard, and 7035 and 7036 are both greys.

Step 2: name the surface and the product type

Before you discuss colour, tell the counter what you are painting. The product decides more than you might think.

• Interior walls and ceilings: a water-based emulsion, usually matt or with a slight sheen.
• Interior woodwork, doors and skirting: a trim paint, often water-based satin or a solvent-based gloss.
• Exterior timber, such as front doors and window frames: an exterior wood paint designed to move with the timber and cope with weather.
• Masonry, render and brick: a masonry paint, often with a slightly textured or flat finish.
• Metal, such as railings and gates: a metal paint, sometimes direct-to-metal, sometimes needing a separate primer.

Each type has its own binder and its own way of holding pigment, so each will show a RAL colour slightly differently. A white in a flat masonry paint looks chalkier than the same white in a gloss door paint. That is normal, and it is the main reason I tell people never to judge a colour across two different products and expect them to agree.

Step 3: choose the gloss level

Gloss changes how a colour reads. A higher gloss reflects more light from the surface, so colours look deeper and more saturated, and every bump in the surface shows. A lower gloss scatters light, so colours look slightly lighter and softer, and imperfections hide better.

Ask what finishes the product comes in. Typical choices are matt, eggshell or satin, and gloss, though names vary between makers. Pick the finish before the shop tints, because changing the finish means a different base and a different formula.

Step 4: ask for a sample pot first

For anything visible and large, buy a sample pot, or a small tin, in the actual product and finish you plan to use. Paint a large piece of card or lining paper with two coats, let it dry fully (wet paint is usually darker), and look at it in daylight in the place it will live. Screens are no help at this stage; why RAL colours look different on every screen explains why the swatch on your phone and the paint on your wall will rarely agree.

Some products are not sold in sample sizes. In that case, ask whether the shop can tint the smallest tin available, or paint a test area somewhere out of sight first.

Step 5: keep everything in one batch

Tinting machines are very repeatable, but bases vary slightly from one production batch to the next, and colourant dispensing has small tolerances. Two tins mixed months apart in different shops can differ. Even two tins mixed on the same day can differ a little.

The safest habits:

• Order enough for the whole job in one go, with a margin.
• Ask the shop to mix all the tins at the same time from the same batch of base, if they can.
• Before you start, pour all the tins of one colour into a larger clean bucket and stir (decorators call this boxing). Then every part of the wall gets the same mix.
• Keep the label or receipt with the formula on it, in case you need more later.

A worked example: a front door, its frame and a hallway wall

Say you are painting a timber front door and its frame in RAL 9010 pure white, and the hallway wall behind it in RAL 7035 light grey. The screen approximations on this site are about #F7F9EF for 9010 and #CBD0CC for 7035, which tells you only that one is a soft, slightly warm white and the other a pale cool grey. That is three surfaces and two different products, so here is how I would order it.

The door and frame

The door is exterior timber, so you need an exterior wood paint, not an interior trim paint. You would ask for "RAL Classic 9010 in your exterior wood paint, satin" (or gloss, if you like the traditional look and the door is in good condition).

Now the quantity. A typical front door is roughly 2 metres by 0.85 metres, so about 1.7 square metres per face. Painting the outside face and the edges, with panels and mouldings adding surface, call it 2 square metres. The frame and any fixed glazing bars add maybe another 1 square metre. That is about 3 square metres per coat.

Many exterior wood paints quote a spread rate somewhere around 10 to 14 square metres per litre per coat on smooth, primed timber. Check the data sheet for your product, because the figure varies. Using a cautious 10:

• Two finish coats on 3 square metres is 6 square metres of painting, about 0.6 litres at that rate.
• A 750 ml tin of finish paint covers that with a little to spare.
• Add whatever primer or undercoat the system needs, which may be a separate product and not tinted at all.

White on a door is unforgiving, so take the larger tin if the next size up is only a little more. A spare half-litre for touch-ups after a winter is worth having, and it will be from the same batch.

The hallway wall

The wall is interior plaster, so you need an interior emulsion. Ask for "RAL Classic 7035 in your interior emulsion, matt" (or a wipeable matt or eggshell if the hallway gets knocked by bikes and shopping bags).

Measure the wall. Say it is 4.2 metres long and 2.5 metres high: 10.5 square metres. Take off the door opening, about 1.8 square metres, which leaves roughly 8.7 square metres. Two coats is 17.4 square metres of painting.

Emulsions often quote somewhere around 10 to 14 square metres per litre on smooth, sealed plaster. At 10, you need about 1.75 litres. A 2.5 litre tin covers it with enough left for touch-ups. If the wall is new plaster, it will need a mist coat or sealer first, so follow the maker's guidance and allow extra.

Why the frame and the wall will never look identical

Notice that the door frame (exterior wood paint, satin) will sit right next to the wall (interior emulsion, matt). Even if both were the same RAL number, they would look slightly different because of the product and the finish. Here they are different colours, which is easier: a soft white frame against a pale grey wall makes a clean edge. If you ever want a door frame and wall in the same RAL number, buy sample pots of both products and paint them next to each other before committing.

A short checklist for the counter

1. Write down "RAL Classic" and the four-digit number.
2. Know what you are painting, inside or outside, and what it is made of.
3. Choose the finish before tinting.
4. Ask which base the formula uses, if you are curious, and whether the formula exists for this product or is borrowed from another.
5. Buy a sample pot or small tin first for large or visible areas.
6. Order the full quantity at once, with a margin, and mix the tins together before starting.
7. Keep the formula label.

If you want more on matching paint across products and makers, the paint matching section collects the longer guides. The last point is the one people skip most often: write the product name, finish and formula on the inside of a cupboard door or in your phone notes the day you buy, because in three years you will want to touch up a scuff and nobody will remember which white it was.