How to split correctly when using bash script

I have a bash command which the result is something like this in my file:

sm-apolo: 2.1-835
sql-apolo: 1.0-2
srmq-processor: 1.0-214

I want to get a result of all items that have sql at the start and only the first part before ":" so need the second part to be removed. Then I want to use the result in choiceParam in Jenkins pipeline to be shown as a drop-down list.
If I run something like this:

names = sh (script: "A command here | grep sql", returnStdout: true).trim()
names_list = names.trim().tokenize("\n")

In the drop-down I get
sql-apolo: 1.0-2

How I can get rid of everything after the name including ": 1.0-2" to show up in the drop down list? something like:

sql-apolo
sql-sxdf
sql-pokf

With GNU grep and a Perl-compatible regular expression (-P):

grep -Po '^sql.*(?=:)'

or:

grep -o '^sql[^:]*'

See: man grep and The Stack Overflow Regular Expressions FAQ