Furuno GP-3500F - Manual (Page 212)

11. VIDEO SOUNDER OPERATION
11-40
Color bar
The color bar shows the relation between echo intensity and echo color on the
screen. The top color (reddish-brown) is the strongest color and the lower colors
the weakest. The bar can be used as a reference to estimate density of a fish
school, fish specifies and hardness of the bottom. The background color can be
selected on the menu screen.
R-BRN
RED
ORANGE
YELLOW
GREEN
LIGHT-BLUE
BLUE
DEEP BLUE WEAK
STRONG
No Signal
Color bar
Minute marker
The minute marker displays a minute worth of time with two colored bars, each
bar 30 seconds in time. It is useful for estimating elapsed time.