Welcome! And, BTW, it's a lady, mates... in all likelihood
I have never kept this one but kept and keep its brothers of the same genus - H. wyckii and H. nemurus.
To get more red in its tail, it needs crustaceans, whole, shell-on. See below for more on its diet in the wild. It is not fussy and should take any and all kinds of frozen-thawed aquatic foods an sea foods and good pellets, like the NLS mentioned; Hikari, Ken's; etc.
If you are new to big predatory catfish, you're starting out with a real hard one

which is not forbidden

IMO, we are not here to tell you what to do or not to do.
Have you read their profiles/data/care sheets on the net (if you did, they'd answer most of your questions)? Like these:
http://www.planetcatfish.com/common/species.php?species_id=19
(Sexing: Males possess a genital papilla just fore of the anal-fin. )
http://www.fishbase.org/summary/Hemibagrus-wyckioides.html
(Feeds on insects, prawns, fish, and crabs)
http://www.seriouslyfish.com/species/hemibagrus-wyckioides/
(Diet: This species is a predator feeding primarily on crustaceans and smaller fishes, although there should be no need to use such live foods in captivity. /// Smaller specimens will readily accept live or frozen bloodworm, Tubifex and most dried foods whereas adults can be offered earthworms, prawns/shrimp, mussels, strips of white fish flesh and larger sinking pellets. /// Juveniles require a relatively high-protein diet whereas adults should not require feeding on a daily basis with 1-2 meals per week sufficient. /// This species should never be fed the meat of mammals such as beef heart or chicken since some of the lipids and other organic compounds contained in these meats cannot be properly metabolised by fishes, causing excess fat deposition and even organ degeneration over the long term.)
http://www.scotcat.com/bagridae/hemibagrus_wyckioides.htm
http://www.fishing-worldrecords.com/scientificname/Hemibagrus wyckioides/show
(
190 lbs (86 kg), 6' specimen, the same as in the FishBase)
http://en.wikipedia.org/wiki/Hemibagrus_wyckioides
http://www.iucnredlist.org/details/180905/0
http://eol.org/pages/208171/details
http://ffish.asia/?p=none&o=ss&id=244
Do you have a plan for when it gets to 2'? 3'? Unlikely but not impossible 4'? Albeit, again, it is highly unlikely yours will reach over 3'.
From this:
http://www.fishbase.org/photos/thumbnailssummary.php?ID=26973# -- 20+ kg, two pics of a 35 kg fish, and 86 kg:
