It’s worth doing your research before you invest in warm cymbals as there is a lot of choice out there in the drum market.
Warm cymbals deal in subtleties, (both tonal and dynamic) to a far greater degree than brighter cymbals. And, while they tend to be less capable of piercing volume than their bright counterparts, you can guarantee that any cymbal above 18" is going to be loud when hit with all your might.
It’s more a question of frequencies and warm cymbals operate in the darker area of the tonal spectrum.
There is no single type of warm cymbal sound that is considered ideal; rather there are qualities that should all be present in each cymbal, but not necessarily in the same proportions. This balance of warm musicality, trashy overtones and dark undertow is commonly referred to as the cymbal’s complexity.
Rides usually give a woody rather than glassy stick sound, hi-hats are more mellow and silvery as opposed to cutting and crashes tend to be rich and harmonious instead of penetrating.
Many, if not all, warm cymbals are handmade (or at least they certainly claim to be). This guarantees a certain uniqueness to each cymbal. However, don’t assume that two models of a particular cymbal will be the same because the chances are they will differ. Always take your existing cymbals with you when you are trying out a new cymbal so that you can hear whether everything blends to your liking or not.