Amnon,

Colored dimensions are a diagnostic that something is wrong. Go to Tools+Options+Mechanical Design+Drafting, choose the Dimesion tab and scroll all the way down to click the TYPES AND COLORS button. This will tell you what all the colors mean.

I can't seem to create a grey dimension, so I'm not exactly sure what it means.

I get pink dimensions when the 3D part is changed to remove the parent features the dimesion is based on.

There is a little icon (called the ANALYSIS DISPLAY MODE) in the drafting Tools toobar - this icon toggles the diagnostic colors on/off.