The vcr output on most devices is lighter. Not sure why but its something I've noticed before too.
Have you tried a different scart cable? Also try changing the output type in the menu to something other than rgb (since your cable may not be rgb).
Those other 3 connectors are for composite. You can connect the yellow one for video and red and white are audio. The quality of this is far lower than scart though. Personally I would avoid using them.