the color on image segmented

below is a part of my coding, i had try insert gray scale image and for figure 2 it produce the image below,

i want to ask where it state about the color produce in figure 2

%Show the results
 
ifsize(im, 3)==1 % Gray-level image 
img=zeros(sz(1),sz(2));
j=1;
imagesc(im); axis off; hold on; colormap gray; 
 
fori=0:k_max-1
    LL=(L_global_min==i);
    is_zero=sum(sum(LL));
    if is_zero
         img(:,:,1)=img(:,:,1)+LL*c(j,1);
         j=j+1;
 
    end
    if i~=i_ground
        color=[rand rand rand];
        contour(LL,[1 1],'LineWidth',2.5,'Color',color); hold on;
    end
end
figure(2);
imagesc(img); axis off;
end

[Erivelton Gualter]

How about this:

https://www.mathworks.com/help/matlab/ref/rgb2gray.html

Answer 1

[Image Analyst]

imagesc() applies it's own crazy idea of how it thinks you want the image pseudocolored, and it's almost always wrong. I suggest you don't use it -- I never do. Use imshow() instead. If you want a colormap, pick one of your own choosing with the colormap() function.