How to rearrange colormap according to color similarity?

I have a jpeg image which I would like to extract the colormap from it, I have try the rgb2ind() but the result colormap is randomly placed. Anyone know how to rearrange the colormap?

img = imread('2.jpg'); [X,map] = rgb2ind(img,256);

%% this is the colormap i created

%% this is the actual colormap

Anyone please help, thank you in advance.