The Jog wheels on the DDJ SR2 have a few different colour feedback options, which can be configured in the utility settings for the controller. 

By default, the LED ring will display in RED if the jog wheel is set to control decks 1/2 in Serato DJ, or AMBER if the jog wheel is set to decks 3/4. 

This can be changed to either give an indication of the jogwheel 'vinyl' mode state or, the LED ring will display the COLOUR tag saved to the file in Serato DJ. 

To change this you'll need to launch the controller into utility mode;

• close all applications
• With your controller turned off, hold down the [SHIFT] & [PLAY/PAUSE] button on the left deck of your controller and power it on

Once in utility mode, you'll see one of the three [FX PARAMETER] buttons on the right-hand side of your controller illuminated (most likely the first of the three) each [FX PARAMETER] represents a different illumination mode for the jog wheels. 

• [FX PARAMETER1] - Will give colour feedback depending on the active deck as mentioned above
• [FX PARAMETER2] - Will give colour feedback depending on the jogwheel 'vinyl' state; If [VINYL] mode is enabled, the jog wheel will be blue. If Vinyl mode is disabled, the jog wheel will not illuminate. 
• [FX PARAMETER3] - Will give colour feedback according to the colour tag saved to the file in Serato DJ.