My first reaction to this post was to ask why a 450 lb calf is being dyed. To me, I wouldn't mess too much with one that young.
We have only dyed 2 steers in 3 years, and that was only for their fat show.
I personally don't think it is worth the hassle, unless you have a really good one with plenty of hair. It is surprising how good you can make one look without dye. Get some oil and a blower, and block off a couple of hours. It works wonders.
To me, it is a fine line between utilizing your resources and just wasting time and money. We will do things in the fitting and hair care process when they will make a difference. If we believe one of our prospects could be a contender if we build his legs, then we do it. If he is really not ready to be showed yet and is there for the exercise of going to a show, then we don't torch his leg hair just for the sake of doing it.
Clairol Nigro Black. One box will be God's plenty. Dump the dye in a fogger, top it off with show sheen. Fog it on him, and brush down with a plastic scrub brush. Then brush forward, then brush straight up, and then down again. Leave it in for about 25 minutes. Rinse it out for a LONG time...until the water coming off him runs clear. Blow him out really good and get some kind of oil on him. Olive Oil or something super light. Work it down to his skin.
Oh...wear rubber gloves. I am quite sure you knew that.