Wireless Neighborhood in wac720

Hello!

I have three aps wac720 in one office. There are in ensemble mode.. There are, may be, quite near, and i want to wacth how many power receive each ap from each other. I go in tab monitoring/ensemble/Wireless Neighborhood: i got a table: i understand i have each ap, and the ssid that receive each ap. I dont understand:

-i have some color like blue,  grey,... What does it indicate?

-i have some number/value like 25, 16,... I hope a rssi power (Like -45dB, -65db,...). What does these values mind?

 I have look for in manual, it indicate the same, but it doesnot explain the colors or value what they are measuring, that they meant.

Can you explain what doest meand the colors and values?

Thank you!