Page 6 of the e-book (the part titled "Choose your wardrobe colors first") has an example of accent color.
I'm not sure what is meant by jewel color either. If it's literally jewel colors, then there's an answer from the WiseGeek - "Jewel tones are rich color tones which resemble well known gemstones, either precious or semi-precious. [...] Some examples of jewel tones include emerald green, amethyst purple, ruby red, topaz yellow, sapphire blue, tourmaline green, and turquoise blue." The description makes me think that these are colors that look great on a Winter. I don't know about the rest of us. These colors were the rage in 2007/2008.