Materials/color respond to light intensity/color just like in real life. If trying to match, e.g., a paint swatch to how it appears in a 'light box' in a paint store - then you need to exactly reproduce that intensity and color of light.
If super pastel, then you probably have some post-effects turned on in Artlantis.
Karl
One of the forum moderators
AC 28 USA and earlier • macOS Sonoma 14.7.1, MacBook Pro M2 Max 12CPU/30GPU cores, 32GB