Well, yellow isn't good, they really should be white. If they are the little elongated greasy looking yellow slugs they are bad but without good ones to compare them with it might be hard for you to tell. Any chance of a picture? I would think slugs would go bad quickly but I’ve never kept them around long enough to be sure. Also, if you get the chance you can candle them in a dark room with a small flashlight and look for veins.
Opinions on maternal incubation vary. Most people prefer to use an incubator where they control the process rather than trusting the female. However, if your cage holds the proper and stable temp and high humidity she should have an excellent chance of hatching any good eggs. What sort of cage is she in, how is it heated, and how is the heat controlled? What's the humidity like? How about visibility (it's probably best that she's hidden and disturbed as little as possible)?
They often start eating again within a few days of taking the eggs away. It is recommended that you scrub the cage out good to get rid of the egg smell to help get her out of the incubating mode if you pull the eggs.
It's hard to know what the females think/feel about having their eggs taken. I tried maternal incubation for the first time last year on one clutch (100% hatch rate). This year I'm going to try it again with a different female whose clutches I've pulled the last four years (figure she's due to finally see some hatch). My female from last year gained weight back pretty well due to a good appetite after the extra 2 months or so of fasting during maternal incubation.
Best of luck!