On 2 March 2017, Lancôme held a launch in London called My Shade. My Power. It put 40 women in front of 40 shades of one foundation, Teint Idole Ultra Wear, and the press release credits a L'Oréal Group chemist, Balanda Atis, with discovering an ultramarine blue pigment that made the deepest shades possible. That is the brand's own account, but I like it because it says something true about foundation: the hard part of a shade range is chemistry, not marketing.

The brand itself is older than most of the category. Guillaume d'Ornano and Armand Petitjean founded it in 1935 and named it after the Château de Lancosme, with a single golden rose as its emblem, and L'Oréal acquired it in 1964. The foundation behind the 2017 relaunch, Teint Idole Ultra 24H, had arrived in 1997, so this is a formula that has been rebuilt, not replaced. My case for a Lancôme foundation is simple: a shade range that started at 40 now runs to 55 in the Natural Matte, and the brand has kept moving the formula toward skin care, describing it as an 81 percent serum base with hyaluronic acid, vitamin E, moringa and prebiotics.

The trick is to choose the finish before the shade. Teint Idole Ultra Wear Natural Matte Foundation is the classic, for a long day. Care & Glow Serum Foundation is the glowier one, and the brand says it has a serum base, buildable medium coverage and hyaluronic and mandelic acid. The Shape Stick and the Ultra Wear Foundation Stick are the portable ones, Skin Idôle 3 Serum Supertint is for days without a full base, and the Dual Finish Powder Foundation is the one for touch-ups. Rénergie Lift with SPF 27 is for the skin that wants a lifting formula, and Care & Glow Serum Concealer is the matching concealer.

Long-wear foundation behaves better when primer goes only where you need it. La Base Pro Oil-Free Longwear Makeup Primer goes on the T-zone and around the nose, and the rest of the face can stay bare.

Then the order. Teint Idole Ultra Wear All Over Full Coverage Concealer goes under the eyes and on spots, and the Skin Refining Setting Powder sets only what needs setting. Long Time No Shine Loose Setting Powder is for a shinier forehead, and the name tells you where I would use it. For colour, Blush Subtil Powder Blush is the gentle option, the Ultra Wear Skin Transforming Bronzer adds warmth, and the C.E. Skin Transforming Highlighter is for the top of the cheekbone.

Génifique Ultimate Recovery Serum sits in this grid because it is the skincare step underneath. A serum before foundation is a sensible habit, and giving it a few minutes to settle keeps the base from pilling.

A pairing I like: the Natural Matte on the centre of the face and the Care & Glow at the edges, so you get coverage where it matters and a glow where skin is thinner.

What I would skip: setting the whole face with powder before a photograph taken with flash. A light dusting on the T-zone is the only part that needs it.

Skin on the day matters more than the shade chart here. A serum foundation suits dry or tired skin, a tint suits a good skin day, and a full-coverage formula is for the day you did not sleep.

NARS Light Reflecting Advanced Skincare Foundation and Clinique Even Better Clinical Serum Foundation with SPF 25 are the two I would compare first, since both put skin care in the name. ILIA True Skin Medium Coverage Serum Foundation with niacinamide is the gentler, more natural finish, and Drunk Elephant Kamo Triple-Peptide Multi-Use Serum Foundation gets you through a rushed morning. ciele tint & PROTECT carries SPF 50+, and tarte's CC color-correcting tinted serum is the one for evening out redness without a full base.

Sisley Paris Phyto-Hydra Teint and Macrene Actives High Performance Tinted Moisturizer are tinted moisturizers for when a foundation feels like too much. Both are for the quiet days.

I wear a skin tint on the face and a full-coverage concealer only on the spots. You look like yourself, only rested.

What I would skip: a full-coverage foundation over skin that has just been exfoliated. Give the skin a day to settle, and use a tint.

Powder looks better pressed than swept. Use a small brush or a puff, press on the centre of the face, and leave the edges alone.

Hourglass Vanish Airbrush Pressed Powder and Charlotte Tilbury Airbrush Flawless Finish Refillable Blurring & Setting Powder are the soft-focus pair. Westman Atelier Vital Pressed Skincare Blurring Talc-Free Setting Powder is the one for people who avoid talc, and LYS Beauty Triple Fix Setting Powder is the one I would keep in a bag for the afternoon. As for brushes, Haus Labs Powder Brush and Saie The All-Over Powder Brush are for a full sweep, Makeup by Mario F2 Dual-Ended Powder Brush does two jobs, and ILIA Finishing Powder Brush is the softest for final dusting.

Use the big brush for the T-zone, the small end of the Mario brush for under the eyes. Different areas need different amounts.

What I would skip: a dense brush loaded with powder and then used straight on the face. Tap it off on the back of your hand first, then press it on in two light passes. You can always add more, and you cannot take it off once it has settled into texture.

The Natural Matte is where I would point anyone first, because the shade range is the point of the story. Get matched in daylight, buy one concealer to go with it, and wear it for a full day before you add anything.

Then bring in the serum version for winter and a powder for the T-zone, and keep one stick in a bag for the times a mirror finds you in the afternoon. Forty women stood in London in 2017 to prove a foundation can fit. You only need to find the one shade that fits you. If you want to keep browsing, I also put together Chanel Foundation, Shade by Shade and e.l.f. Concealer.