Ivory and cream, trousers first. White has no season; fabric weight does.
Retired
The Emily Post Institute says white after Labor Day is fine. It's about weight, not color.
Ivory below, dark above
Ivory tapered trousers with a black top and a closed shoe read as winter.
A little sheen
Fluid ivory wide-legs with a tucked knit look like evening, not the beach.
Mix the textures
Lace, knit and satin in one family of whites looks rich, not bridal.
From Maria's edit
Warm whites from Italy for the colder months.