SECTION 01
Check your undertone first
Undertone is a separate axis from depth, so a perfectly matched depth still looks wrong if the undertone is off. Before buying foundation, figure out whether you lean warm, cool, or neutral.
SECTION 02
The vein test and the jewelry test
- iIf the veins on your inner wrist look green, you lean warm; blue or purple, cool; hard to tell, neutral.
- iiIf gold jewelry brightens your face, you lean warm; if silver flatters you more, cool.
- iiiAgainst white fabric, ivory suits warm undertones better; pure white suits cool undertones better.
SECTION 03
Reading the W, C, N on the label
Most brands mark undertone next to the depth number: W for warm, C for cool, and N (or no letter) for neutral. Two shades can share the same number and still look completely different once the undertone letters differ.
SECTION 04
Depth and undertone are two separate problems
Depth is how light or dark your skin is; undertone is which direction the color leans within that depth. Two people at the same depth can need different shade numbers if one is warm and the other cool, so shopping by depth alone leaves undertone unmatched.
SECTION 05
The jaw swatch test and oxidation
Test on your jawline, not your hand, and check that it blends into your neck. Judge it in daylight or near a window, since indoor lighting can shift the color entirely. Foundation also oxidizes after wear, turning slightly darker or more red, so leaning one shade lighter and rechecking after ten minutes is the safer call.
SECTION 06
Beyond undertone, a full reading
The vein and jewelry tests only estimate warm versus cool. A full reading layers value, chroma, and contrast on top of undertone across 16 types. Our tool reads all four axes, including undertone, from a single photo, correcting for lighting before it diagnoses. Your photo is discarded the moment analysis finishes, and the result is free with no sign-up.