He said he will not have a spray-on colour on the night, because "if I start sweating, which I will do, you'll see it running down my face - it's got to be the real deal".
But James admitted he doubts she will head to victory, having been in the bottom two for three consecutive weeks.
"It's big in its own sense, in its own pocket of entertainment, but to the more traditional media it's such an unusual thing so when I was announced to be on the show I think I got one of the most controversial reactions from the general public, a lot of 'Who?"
Tess Daly has joked that being a parent helped prepare her to keep the judges in order on Strictly Come Dancing.
Speaking on BBC One's Breakfast programme, Roberts said: "I did have dance (classes) when I was younger".
Ashley & Pasha chose their Charleston, Stacey & Kevin went with their Argentine Tango, Faye & Giovanni selected their Couples' Choice Theatre/Jazz routine and Joe & Dianne picked their Charleston.
But despite the odds the panel went on to save her each week, the pair have now landed a spot in the coveted Strictly Come Dancing final and Pasha couldn't speak more highly of his partner.
"That is a really good term because it's a bit like a circus out there sometimes on a Saturday, with the judges", she said.
Defending her from the criticism she has faced over her dance experience he said: "Every year we have celebrities who people think have more of an advantage over someone but from my point of view it's a completely different ballgame and you still have to put so much work to master ballroom and latin because it's so difference from all other dance styles". "It is such a process throughout the week - you doubt yourself as you think about how is this all going to come together on Saturday", she explained.
She has, after all, given us plenty of memorable moments during the series, from the early days of her "Minions"-themed Jive and "Doctor Who"-inspired Tango to her emotional Musicals Week routine and fun-fuelled Showdance".
"That dance was better than most of you will ever know Pasha is so b****y clever!"
"I have smiled so much and as if I couldn't love it any more".