sure it was, protestants hadn't been invented then.Catholics wrote...raher interpreted , edited, copied(by hand) the bible, established churches, monastaries, libraries, helped governments, taught Christianity as they had been instructed by Christ to do so, in fact, brought you the Christian religion as you know it today....say thanks.
Where in the Bible does it say it was written by Catholics since that word was not used until a long time afterwards? The only thing Catholics did was to bring the written books together. They had nothing to do with writing it.