Smoke is a fashionable matte grey colour with a slight purple tint that looks amazing on everyone. Smoke only works on pre-lightened level 7 hair or lighter (refer to listing images). On level 5 and 6 hair, it would turn your hair into a dark brown shade instead of grey.
The colour turns out the best when it's applied to non-brassy hair. If you are starting off with a yellowish blonde base, try toning it with Iris to remove the yellow hues before going in with Smoke. Because of the purple tint, Smoke would show up as a greyish-purple on level 9 and 10 hair.