Formatting errors in my Bibliography

Hi guys I recently handed in an assignment (3rd year student at the University of Birmingham), I just checked back and noticed that although I complied with the correct Oscola referencing, some of the references are a slightly different shade of black, additionally there are 2 mistakes in my references. This is the first time its ever happened to me and I am unaware of the consequences.

Hi,
Try not to worry, I doubt the slightly different shade of black will make a difference and if there are small referencing mistakes these might not even be noticed by your marker.
-Jasmine (Lancaster Student Ambassador)

The colour differences may well not be noticed.
Referencing inconsistencies or errors are more likely to be picked up, but depends on the extent of them. The outcome is likely to depend on exactly the issue and also what year you're in.
If its just inconsistencies in formatting (e.g. you forgot to put quotes around the title of an article or put the name of a book in italics) but all the relevant bibliographic information is there and you have cited references in your text, then you might be dinged a couple of marks but unlikely to be a major factor. Although you may be hit harder on marks in latter years of the degree compared to first year.
If you haven't properly attributed something (missing in text citations, missing bibliographic references, etc) them this may be more of an issue. In first year it's probably not a huge matter but will probably be flagged. In latter years of the course they may deem this constitutes plagiarism if it appears you are otherwise presenting someone else's ideas as your own.
It's hard to say exactly what the situation may be without knowing exactly what the "mistakes" may be.