No problem.

UVB bulbs lose most of their output within about 6 months, some claim to last for a year. So I'd get a new one if you're using an old one. I'd go for Zoo Med or Arcadia personally, they're products are of decent quality from Europe.

I've just noticed you said you've had them only for a week. I think you may as well just leave them in the tank unless problems do occur, so not to stress them. Watch out for watery faeces to see if they continue as this is a bad sign. You usually will be able to see them clear enough without quarantining, they'll generally poo on the plants or side glass. Probably was just shedding or needing to settle in. The tree frogs I currently have, Hyla Cinerea, change colour all the time.

I wouldn't treat any frogs unless absolutely necessary, recommended by a vet that has experience with frogs and has the book amphibian medicine and captive husbandry by wright and whitaker on hand. As long as your frogs are captive bred they should be clean.