Color theory is one of those topics that sounds academic but is genuinely practical once you understand it — because it explains exactly why certain lip gloss shades make you look radiant and others make you look tired, even if the shade looked beautiful in the tube.
It comes down to a few core principles: undertones, color temperature, contrast, and saturation. Once you have a working understanding of all four, you'll never buy a gloss shade that doesn't work for you again.
Undertones: The Foundation of Everything
We touched on undertones in the shade guide, but for color theory purposes it's worth going deeper. Your skin has two layers of color at work simultaneously: your surface tone (the general fairness or depth of your complexion) and your undertone (the secondary hue that influences everything).
Undertones are warm (yellow, golden, peachy), cool (pink, blue, red-adjacent), or neutral (a balance of both). They don't change with sun exposure, seasons, or age.
The reason undertones matter in gloss is this: when a gloss shade shares or complements the undertone in your skin, your skin looks healthier, brighter, and more cohesive with the product. When a gloss shade fights your undertone, there's a visual disharmony — you look "off" in a way that's hard to pinpoint but immediately noticeable.
Example: A coral gloss (warm undertone) on cool-undertoned skin creates visible tension — the warmth of the gloss makes the pink or blue undertone of the skin look more pronounced, creating an awkward clash. But that same coral on warm-undertoned skin creates harmony — the warmth of both reads as intentional and radiant.
Color Temperature: Warm vs. Cool in Practice
Every lip gloss shade has a color temperature — it leans either warm or cool. This is separate from the shade category itself. A pink can be warm (peachy pink, bubblegum) or cool (mauve, dusty rose). A nude can be warm (caramel, golden nude) or cool (taupe, greige). A red can be warm (tomato red, orange-red) or cool (true red, blue-red).
Matching or complementing temperature: The simplest approach is to match gloss temperature to your skin undertone. Warm undertone skin + warm gloss = harmony. Cool undertone skin + cool gloss = harmony.
Contrast as an intentional choice: Sometimes a temperature contrast is absolutely the point. A cool mauve gloss against warm-undertoned skin creates a deliberate, striking contrast that can be beautiful and intentional — as long as you understand that's what you're doing. The contrast needs to be significant enough to read as intentional rather than accidental.
Saturation: How Much Color Is Too Much (or Not Enough)?
Saturation refers to the intensity or purity of a color. A fully saturated red is a pure, vivid red. A desaturated red leans dusty, muted, or mauve-adjacent.
The right saturation level in a gloss depends on your natural lip color and your skin tone's natural saturation.
High saturation skin tones (deeper complexions with rich, vivid natural color) can carry more saturated lip shades because the intensity is proportional. A highly saturated vivid red on a deep skin tone looks balanced and intentional.
Lower saturation skin tones (very fair or light skin with subtle natural coloring) can be overwhelmed by very high-saturation shades that appear to "jump off" the face without integrating. Slightly desaturated versions of bold shades — a dusty berry instead of a vivid berry, a muted rose instead of a hot pink — tend to look more cohesive on these complexions.
Very desaturated shades on any complexion can look washed out or ashy if they're too close to your skin tone in saturation. There's a zone of saturation that's too close to bare skin — it doesn't read as a color choice, it just looks like your lips but somehow duller. Shade shopping within this zone is how people end up with "that nude that looks wrong on me but I can't figure out why."
Contrast: Playing With the Relationship Between Lips and Skin
Contrast is the difference in value (lightness or darkness) between your lip color and your skin tone. This is one of the most powerful and underused tools in lip color selection.
High contrast looks: A bold, deeply saturated shade on fair or light skin creates high contrast. This is a very striking, deliberate look — it draws the eye immediately. Classic red lip on pale skin is the ultimate example.
Low contrast looks: A shade close in value to your natural skin tone creates a low-contrast look that's harmonious and softer. The no-makeup nude lip is the ultimate low-contrast example.
Medium contrast: Most everyday lip looks live here — a shade that's noticeably different from bare lips but doesn't create the same drama as a high-contrast look. Medium contrast is the sweet spot for most occasions.
The mistake to avoid: A shade that creates unintentional low contrast — like a gloss that's slightly darker than your skin but not different enough to look like a choice. This is the "why does this shade look wrong" problem. You need either genuine low contrast (a real nude) or enough contrast to read as a color decision.
The Role of Value in Gloss Specifically
One more concept: value, which refers to the lightness or darkness of a shade. Glosses affect perceived value through their finish — the high shine of a gloss makes any shade read as slightly lighter and more luminous than the same shade in a matte formula.
This means:
- A shade that might look heavy in matte reads as more approachable and fresh in gloss
- Very dark matte shades that can look severe translate more wearably in a glossy formula
- Light shades appear even more luminous in gloss, which can either be beautiful (barely-there luminosity) or look too light (the "ashy" effect if the shade was already very pale)
When you're shopping for a gloss shade and you've seen the matte version on someone else, assume the gloss formula will look slightly lighter and more fresh than what you saw.
Building a Color Theory–Informed Gloss Wardrobe
With all of this in mind, here's how I'd recommend approaching your gloss collection:
Anchor with your undertone: One or two shades that are firmly in harmony with your undertone — your warmest everyday nude or your most natural-looking pink. These are your can't-fail, wear-them-without-thinking options.
Explore contrast intentionally: Pick one shade that creates more contrast than your everyday choices — a deeper berry, a bold coral, a real red. This is your deliberate-choice shade for when you want your lips to be noticed.
Add a low-saturation option: A slightly muted, dusty, or desaturated version of a shade you love for occasions when you want color but not intensity.
Include a shimmer: A neutral shimmer gloss that works with your undertone adds dimension to any look and photographs beautifully.
Keep a clear: Undertone-neutral and always right.
That's a complete gloss wardrobe, built with genuine color intelligence behind every choice.
Every Glossed by Jenna shade is developed with undertone and color balance in mind. Find your most intelligent gloss choices in the collection.