In the SQL query editor where you create transformations, we've changed the color coding to match the editor used in Data Integration. Operators are now displayed in blue, double-quoted strings and base texts are in black, single-quoted strings are in red, and comments are in green. Also, if you get a validation error, the editor now underlines the section of your SQL where the error is present. For the instructions to write custom transformations, see Creating custom transformations.