^start of line
Negated Character Class[^:]* *matches any number of characters outside the set below:
:the literal : (5810 / 728 / 3A16)
:the literal : (5810 / 728 / 3A16)
\s*any whitespace character, repeated any number of times
Negated Character Class[^.]+ +matches at least one character outside the set below:
.the literal . (4610 / 568 / 2E16)
.*any character (except for line terminators), repeated any number of times
g modifier: global. Finds all matches instead of stopping after the first
m modifier: multiline. Causes ^ and $ to match the start and end of each line, not only the start and end of the string