Modes were introduced with software version 1.4.0. If your fixture is not running 1.4.0 code, you’ll need to update it.
To see what mode your fixture is in, power cycle your fixture and the software version will flash on the 7-segment display while the fixture boots. If you’re using RDM from a console to address your fixtures from a console or Net3 Concert, you’ll have access to the software version as well.
If you need help updating your fixture, please refer to your fixture the user manual available on the website: http://www.etcconnect.com/Products/Lighting-Fixtures/ColorSource/Documentation.aspx