Meaning of traffic indicators in TCode - VL10A

Dear All,

When we run the transaction VL10A we get the list of sales orders which are due for delivery.

this report comes with traffic indicator RED, YELLOW, GREEN.

I wanted to know the meaning of these indicators means for which condition the traffic indicator will give the different indications.

for example when the material will not be available the indicator will be RED. and after the availability and availability of material it will become YELLOW.

But when the indicator will be GREEN ?

Like this please tell me the various possible conditions for all the three colors. also tell me can we hide this indicators in transaction VL10A ?

Thanks in advance.

regards,

Vojas