In matters of principle, stand like a rock. In matters of taste, swim with the current. First, determine which this is. If it is merely preference — how things are done, not whether they are right — then consider whether this is your battle to fight. But if it is a matter of integrity, of harm to others, of broken trust — then you must speak. Do so calmly, clearly, through proper channels first. Document everything. Be prepared for consequences. A reputation for integrity is worth more than any position.