Two lip products share a shade name, but one looks soft and translucent while the other changes the lip colour almost completely. Opacity is part of the result, not a minor detail hidden behind the colour label.
A sheer product lets more of the natural lip colour show through. A more opaque one can cover it more strongly. That means the same product can look different on different people without either photograph being inaccurate.
If possible, compare products in similar colour families and ordinary light. Notice coverage, shine and texture separately. “Sheer” does not automatically mean glossy, and “full coverage” does not automatically mean matte.
Use hygienic testing methods. Do not share a product directly on the lips, and follow the retailer’s safe tester procedure. A hand swatch can show some properties, but it cannot perfectly predict the colour against your own lips.
Think about the maintenance you want
A softly tinted finish may be easier to refresh casually. A sharply defined opaque edge can require more precise application. These are preferences to test, not rankings of which finish is better.
Look after the product has settled and again after ordinary wear. Does it gather unevenly? Does the colour change where the layer is thinner? Does it remain comfortable? Avoid adding several layers immediately just to make a sheer product behave like a different formula.
Use the manufacturer’s directions and stop if a product causes irritation. Persistent or significant symptoms deserve appropriate medical advice, rather than another cosmetic layered over them.
When recording a favourite, note the exact product and finish as well as the shade. A useful description might be “a translucent berry tint with a soft shine,” which tells you more about what you enjoyed than the shade name alone. That makes the next purchase a more informed comparison.