Having color indicate any sort of state on User Interfaces is generally a bad idea.

The number of people in society that are color blind is surprisingly high! Approximately 8% of males have red green blindness:
http://en.wikipedia.org/wiki/Color_blindness#Prevalence

Also having blue on a gray background can be quite hard if not impossible to distinguish from normal black text depending on monitor settings.

Having a symbolic visual indicator like a Astrix "*" would be a easy and great improvement.

The current statement of saying that blue items are required is also kind of hard to read when filling our a form and should be improved.