Update 4.0.2 to 4.0.3

It`s safe to overwrite files ?

We can uload files from 4.0.3 over 4.0.2 ?

you should upgrade through the upgrade center. You will get a message in the admin area when it's ready for your store.

I did and now My site front end shows Fatal error

Fatal error: Uncaught exception 'Exception' with message 'expected color value: failed at background-color: lighten(@base, 45%); line: 2'