How much different colors will be displayed

Question

I am using a waveshare 64x64 panel along with Pico w running circuitpython

For more info on the display https://www.waveshare.com/rgb-matrix-p3-64x64.htm

i initialized the rgbmatrix as follows

 matrix = rgbmatrix.RGBMatrix(
width = width_value, height=height_value, bit_depth=bit_depth_value,
rgb_pins = [board.GP2, board.GP3, board.GP4, board.GP5, board.GP8, board.GP9],
addr_pins = [board.GP10, board.GP16, board.GP18, board.GP20, board.GP22],
clock_pin = board.GP11, latch_pin=board.GP12, output_enable_pin=board.GP13,
tile = chain_height, serpentine=serpentine_value,
doublebuffer = True)

the bit_depth is assigned as 6. It cant take more than 6 as values. But the frambuffer is of the format RGB565 making it 16 bit.

for more info https://docs.circuitpython.org/en/latest/shared-bindings/rgbmatrix/index.html

MY doubt is that how much colors can this we display. ? is it 65,536 or 64 ?

How can i check if my file is RGB565 format or not..?