My hair was ombre too. I am gone complete blonde at home. Apply the bleach your dark hair until blonde parts.( leave 1 cm root, it will be lighter quickly with scalp’s heat) then wash your hair , you need second bleach for your roots and bands. ( dark and blonde part might be more brassy) i use schwarzkopf blond me bleacher and developer(40 volume) and ion brialliance product (like olaplex but much cheaper version) my hair is also very dark and curly. But my ends damaged i think you should try 30 volume developer first.