The mutations you mention are very different in their expression of colour. Violet lacewings paired to a cobalt type lacewing would probably be the best way as I think that a double factor violet mauve lacewing would be the darkest blue type. Any other opinion would be interesting.
Of the three mutations the clear tail is probably the darkest blue type. To breed this you would need clear tail visuals. Pair in a similar way mentioned as for the lacewing and you would have a diamond in your hands.