You can use the image_proc node to get the color version of the image:

ROS_NAMESPACE=camera_front_center rosrun image_proc image_proc
ROS_NAMESPACE=camera_back rosrun image_proc image_proc

There are possible cameras front center and back (facing downwards)

/camera_front_center/image_raw
/camera_back/image_raw

You can also use the /aqua/state topic to get depth and attitude information.