Problem with using a lot of colors for consecutive lines

I am plotting these consecutive lines (the # of lines can be anywhere btw 1 and 300+) I need each line to be represented with a different color and no two consecutive lines should have similar colors (the distinction of lines is important for the user) currently I am using the following code, but this sometimes produces colors with similar hue/tone:

n = number of consecutive lines as necessary
C = rand(n,3); 
for i=1:1:n
    p = plot3( [x(i) x(i+1)], [y(i) y(i+1)], [z(i) z(i+1)], 'Color',C(i,:))
end

the problem is that I don't want to use alternative colors since it's important to be able to recognize different parts of my line structure, which happen to be a protein.

any suggestion is appreciated

Answer 1

[Image Analyst]

Here's one way. Just make sure that the distance between consecutive lines is more than some minimum distance in RGB space. I also make sure it's not close to the background color of the chart.

% Makes a plot of lines making sure that each line is a much
% different color than the line before it.

% Initialization stuff.
clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clearvars;  % Erase all existing variables.
workspace;  % Make sure the workspace panel is showing.
format longG;
format compact;
fontSize = 20;

%--------------------------------------------------------------
% Main routine begins here.
numberOfLines = 300; % Number of consecutive lines as necessary
% Specify the miniumum acceptable distance in 3D RGB space.
minAcceptableColorDiff = 0.5;
% Specify the background color (we'll use white).
backgroundColor = [1 1 1];
numGoodColors = 1;
% Keep track of distances just for fun.
distance = zeros(numberOfLines, 1);  
backgroundColorDistance = zeros(numberOfLines, 1);
% Start off with some arbitrary color.
listOfGoodColors(numGoodColors, :) = rand(1,3);
% Use a random walk to find subsequent good colors.
% They must be at least minAcceptableColorDiff
% away from the prior color.
tic;
for k = 2 : numberOfLines
  % Initialize.
  lastColor = listOfGoodColors(numGoodColors, :);
  % Now try to find colors that are minAcceptableColorDiff
  % away from the last color.
  while (distance(k) < minAcceptableColorDiff) ...
    || (backgroundColorDistance(k) < minAcceptableColorDiff)
    potentialColor = rand(1,3);
    % Find the color difference.  Keep track as function of k just for fun.
    distance(k) = sum((potentialColor - lastColor).^2);
    % Also check the distance of this color from the
    % plot background color.
    backgroundColorDistance(k) = sum((potentialColor - backgroundColor).^2);
  end
  % You get to here when you got a good color.
  numGoodColors = numGoodColors + 1;
  listOfGoodColors(numGoodColors, :) = potentialColor;
end
toc;
%--------------------------------------------------------------

% DONE.  Done with creating the list of colors to use.
% Now plot some lines using those colors.

figure;
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);

% Now plot the lines at random locations.
x = rand(numberOfLines, 1);
y = rand(numberOfLines, 1);
p = zeros(numberOfLines, 1);
pauseForUser = true;
for k = 2 : numberOfLines
  p = plot( [x(k-1) x(k)], [y(k-1) y(k)], ...
    'Color', listOfGoodColors(k,:),...
    'LineWidth', 3);
  if k <= 2
    xlim([0 1]);
    ylim([0 1]);
    xlabel('X', 'FontSize', fontSize);
    ylabel('Y', 'FontSize', fontSize);
    title('Random Color Lines', 'FontSize', fontSize);
    hold on;
  end
  if pauseForUser
    message = sprintf('Do you want to continue and plot line %d of %d',...
      k, numberOfLines-1);
    button = questdlg(message, 'Continue?', 'Yes', 'No', 'Non-stop', 'Yes');
    drawnow;  % Refresh screen to get rid of dialog box remnants.
    if strcmpi(button, 'No')
      return;
    end
    if strcmpi(button, 'Non-stop')
      pauseForUser = false;
    end
  end
end