draw colored binary file

I am trying to make vertical lines and my code generate white and black vertical lines. what do i have to do to change the color of white line to grey color or choose any color from 0 to 256.

number_of_rows = 1000; white_segment = ones(number_of_rows,1)*1; black_segment = zeros(number_of_rows,2); white_n_black_col = [black_segment,white_segment]; white_n_black_bars = repmat(white_n_black_col,1,(1000/3)); imwrite(white_n_black_bars,'vertical_bars2.bmp');

Answer 1

[Image Analyst]

When you call ones, multiply by some number between 0 and 1.

white_segment = ones(number_of_rows,1)* 0.4;

Or else use uint8

white_segment = ones(number_of_rows,1, 'uint8')* 137; % Or whatever number you want.