Colors on Multi-trace Plots

I've recently encountered a problem I've never seen before. I've read the help documentation, but cannot find the solution.

When you plot multiple curves in a figure, using "plot," for example, MATLAB usually uses different colors for the different curves. But my MATLAB suddenly began to plot all curves blue!

How can I fix this, and avoid it in the future?

Any help would be appreciated.

Answer 1

[Image Analyst]

Somehow your ColorOrder got messed up. See this demo to see how you can see your current color order and how you can set it to be whatever you want:

% Unless you specify the 'Color' property when you plot,
% plots are plotted according to the 'ColorOrder' property of the axes.
% This demo shows how you can change the default color order of plots.

clc;    % Clear the command window.
close all;  % Close all figures (except those of imtool.)
clear;  % Erase all existing variables.
workspace;  % Make sure the workspace panel is showing.
fontSize = 18;

% Make 20 plots, with 25 data points in each plot.
numberOfDataSets = 20;
x = 1:25;
y = rand(numberOfDataSets, length(x));
% These y would all be on top of each other.
% Separate the plots vertically.
offsets = repmat((1:numberOfDataSets)', [1, length(x)]);
y = y + offsets; 

% Get the initial set of default plot colors.
initialColorOrder = get(gca,'ColorOrder') % Initial

% See what the colors look like when plotted:
subplot(2, 1, 1);
plot(x,y, 'LineWidth', 3);
grid on;
caption = sprintf('%d plots with the Initial Default Color Order (Note the repeating colors)', numberOfDataSets);
title(caption, 'FontSize', fontSize);
xlabel('X', 'FontSize', fontSize);
ylabel('Y', 'FontSize', fontSize);

% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]); % Maximize figure.
% Give a name to the title bar.
set(gcf,'name','Image Analysis Demo','numbertitle','off')

choice = menu('Which ColorOrder do you want?', 'jet', 'random', 'hsv', 'hot', 'cool', 'spring', 'summer',...
  'autumn', 'winter', 'lines', 'gray', 'bone', 'copper', 'pink');

% Make a new axes:
subplot(2, 1, 2);

% Create a new colormap that will define the new default color order property.
switch choice
  case 1
    newDefaultColors = jet(numberOfDataSets);
  case 2
    newDefaultColors = rand(numberOfDataSets, 3);
  case 3
    newDefaultColors = hsv(numberOfDataSets);
  case 4
    newDefaultColors = hot(numberOfDataSets);
  case 5
    newDefaultColors = cool(numberOfDataSets);
  case 6
    newDefaultColors = spring(numberOfDataSets);
  case 7
    newDefaultColors = summer(numberOfDataSets);
  case 8
    newDefaultColors = autumn(numberOfDataSets);
  case 9
    newDefaultColors = winter(numberOfDataSets);
  case 10
    newDefaultColors = lines(numberOfDataSets);
  case 11
    newDefaultColors = gray(numberOfDataSets);
  case 12
    newDefaultColors = bone(numberOfDataSets);
  case 13
    newDefaultColors = copper(numberOfDataSets);
  otherwise
    newDefaultColors = pink(numberOfDataSets);
end
% Note: You can build your own custom order if you want, 
% just make up a array with numberOfDataSets rows and 3 columns
% where each element is in the range 0-1.

% Apply the new default colors to the current axes.
set(gca, 'ColorOrder', newDefaultColors, 'NextPlot', 'replacechildren');

% Now get the new set of default plot colors.
% Verify it changed by printing out the new default color set to the command window.
newColorOrder = get(gca,'ColorOrder')

% Now plot the datasets with the changed default colors.
plot(x,y, 'LineWidth', 3);
grid on;
caption = sprintf('%d plots with the New Default Color Order', numberOfDataSets);
title(caption, 'FontSize', fontSize);
xlabel('X', 'FontSize', fontSize);
ylabel('Y', 'FontSize', fontSize);

msgbox('Done with ColorOrder demo!');

[Dave]

Thanks, IA. I ran this script and received the error message "Maximum Recursion Limit of 500 Reached". Then it said the limit could be increased, but also cautioned against setting it too high or dire things could happen and crash MATLAB. No other output. Please advise.

Also, I really just want to reset to defaults, rather than change it. Can that be done simply?

Finally, what kind of things could scramble the ColorOrder? I've not been doing anything complex graphically, just plotting some data.

[Image Analyst]

Bizarre. I just copied from above, pasted it into a brand new m-file window and it ran fine with no errors whatsoever. Did you do the same? There should be no recursion happening at that I can see. Maybe you can try again. Set a breakpoint to see if it keeps stopping at that breakpoint over and over again and step through it. It should stop only once since it's not doing recursion.

I would think the default ColorOrder should be reset every time you open a new axes and every time you open MATLAB.

[Dave]

I re-ran it, and it appeared to work fine. Here was my "original ColorOrder"

initialColorOrder =

         0         0    1.0000
         0    0.5000         0
    1.0000         0         0
         0    0.7500    0.7500
    0.7500         0    0.7500
    0.7500    0.7500         0
    0.2500    0.2500    0.2500

Don't know if that's the default ColorOrder or not. I guess I should restore it to the default, if I could do that.

Thanks

[Dave]

However, I plotted another plot with two functions plotted, and both curves on the plot were blue ???

[Dave]

Thanks for the help, IA, I think I've got it.

[Image Analyst]

That ColorOrder looks fine. The only thing I can think of is you must have an argument to your plot() function that says 'b-', which forces the plots to be blue.