Wikipedia:Added or removed characters

The numbers appearing on watchlists, user contributions, page histories, and the recent changes page show the increase or decrease in the number of bytes in the page. On the English Wikipedia, this is normally the same as how many characters have been added or removed from a page in that edit. A positive green number (+xx) indicates the number of bytes that have been added, and a negative red number (−xx) indicates the number of bytes that have been removed. Numbers with absolute values above 500 are shown in bold, for example (+794) and (−2,412) instead of (+79) and (−241). A gray zero (0) indicates that the number of bytes have not been changed. Hovering over the number will show the page size after the change.

To remove these numbers completely from all pages, add

.mw-plusminus-pos {display: none;}
.mw-plusminus-neg {display: none;}
.mw-plusminus-null {display: none;}

to your personal CSS.

To make the numbers black instead, add

.mw-plusminus-pos {color: black;}
.mw-plusminus-neg {color: black;}
.mw-plusminus-null {color: black;}

to your personal CSS.

Recent changes patrollers who want the numbers bold and brightly colored so they are easier to spot may add

.mw-plusminus-pos {
    color:green;
    font-weight:bold;
}
 
.mw-plusminus-neg {
    color:red;
    font-weight:bold;
}

to their personal CSS.

Be sure to clear your cache after making these changes.