Is it possible to to highlight column when choosing value?
For example, with statement Insert into test_table(col1,col2,col3) values ('v1','v2','v3') i want to highlight col2 when I'll click on 'v2' or highlight col2 when I'll click on 'v2'
Sorry, I don't think that is possible.
As John already mentioned, don't see a way of doing this directly. However, if I understand the use case (wanting to make sure your insert values match up to the proper column, etc.) then here's a handy tip that could help a little.
When Toad generates the Insert statement for your existing table (see snap 1 below), it includes comment placeholders inside the VALUES clause (snap 2). While you can't keep these comments inside the VALUES section (wish Oracle would allow that!), highlighting one of these comments also highlights the corresponding column it's associated with in the column list section.
At least this will help you confirm the associated columns for the value/s you're entering. Hope this helps get you part way there.