# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/(:(?![\n])[()#$@-\w]+:)//g;t' <<< ":any-non-whitespace:
:text1:sample2:
:@(1@#$@SD: :s:
:nospace::inbetween: because there are 2 colons in the middle
:nospace:middle:nospace:
"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html