yea, never heard of using purplish lighting in planted tank. the best light source is the sun light... and is not purplish...

i believe you can get a new set of FL lighting. suggest you to DIY. or if you have budget buy those Aquarium units. but still i would just DIY. search the web, it contains a lot of information about DIY aquarium stuff.

dont forget about the substrate and CO2. for low tech plant, you can skip CO2.