Green color will eventually fade away after your soap is cured.
There are many factors that effects color in Olive Oil. Here are few.
Green color: 1. Unripe or half ripe fruits are milled - Oleic Acid is low, up to 0,8
2. Fruits are grinded and milled with leaves.
3. Geographical factors. ( As per my experience, Eastern Oils have greenish color.
Yellow Color: 1. Ripe fruits are grinded and milled - Oleic acid little higher - 0,8 to 2
2. Oil went through oxidation (You cant find these in packages)
Try Virgin Olive Oil but you may still have green color.
Has anyone tried refined (riviera) ? Riviera will be yellow but I have not used it in soaps.