Where to get my God cards checked?

So I want to sell one of my ultra rare God cards so i can buy the secret rare. I only have obelisk the tormentor and it looks 100 % real. No 1st edition, blue back, correct font, the only thing that bothers me is the colors. It doesn't look like the coloring i see in most fakes but I feel like its not exactly like the colors in real. The background of the card is the right shade of blue but Obelisk himself seems just a little more lighter/paler then i expected. So I was wondering if there was a site to guarantee the authenticity of this card of if i should just go to a card shop.