Lim. aromatica and Lim. hippuridoides should be different botanic species.......but they are really close in appearance.
In my experience, the Lim. hippuridoides is more tolerant of different parametres in the tank - making it the safer choise.
Some find Lim. hippuridoides a slow starter, needing some time to adapt to life under water. Not my expetience, though.
When growing, it will grow vigorously and is usually very willing to break new shoots from cut stems.
Purple Colour will adapt to light intensity, more light => more purple colour.
By letting each stem grow to surface, maximum colour will be achieved. When trimming at this point, re-planting the best off-cut's in the group at various lenghts, will automatically bring colour to lower parts - making a nicer appearance.