The lighting requirements would depend on what you need to accomplish with them.

If you need to increase temperature or just add lighting for the vivarium's plants.
Your frogs need no special lighting so if you need to add to the tanks temperature then incandescent bulbs are usually needed and the amount to need to raise the temp would determine what wattage bulb is needed.

If you need to just add lighting for the plants and viewing, you can usually use 6500K color temp compact florescent bulbs which I purchase at Walmart. I buy the 26 watt version and I believe they are listed as daylight bulb but have the 6500K in large print on the front of the package.
They work great with plants and only slightly raise temps by a few degrees.

For night viewing, I use a basic 15 watt red incandescent which also adds a little heat which my WTFs like to sit under at night.