This plant seems to be produced by many growers and as a result can vary from others. Typically, Limnophila aromatica has narrow green leaves, which are purple underneath. Grown under high ligting the colours are pretty special, but reduce the lighting and it tends to become a lot more green. It prefers to have CO2 or at least liquid carbon in order to flourish. Of course a decent substrate goes without saying so don't justs plant it in gravel.
It does best in harder water which is unusual. In VIetnam, they actually use this plant for tea so if you're feeling creative - give it a go.
Finally,as you can see from the pictures it's a really stunning plant once it gets going so can add lots of colour very quickly. It's a plant that certainly WON'T disappoint!