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I am having trouble running this code:

Needs["GraphicsColors"];

u[x_, y_] = FullSimplify[ComplexExpand[Re[g[x + iy]], TargetFunctions -> {Im, Re}]];

v[x_, y_] = FullSimplify[ComplexExpand[Im[g[x + iy]], TargetFunctions -> {Im, Re}]];

w[x_, y_] = FullSimplify[ComplexExpand[Abs[g[x + iy]], TargetFunctions -> {Im, Re}]];

Plot3D[u[x, y], {x, -3, 3}, {y, -3, 3},
  PlotPoints -> {41, 41}, 
  PlotRange -> {{-3, 3}, {-3, 3}, {-0.05, 0.4}},
  ClipFill \[RightArrow] None, AxesLabel -> {"x", "y", ""}, 
  ColorFunction -> Hue]; 

Print["u[x,y]=", Re[f[x + iy]]];

Print["=", u[x, y]];

When I evaluate the code above, I get the following message:

Get::noopen: "Cannot open \!\(\"GraphicsColors\"\). "

What is wrong with this code?

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  • $\begingroup$ Graphics`Colors`​ is now a deprecated package. What functions do you need in there? $\endgroup$ – J. M. will be back soon Oct 13 '15 at 7:11
  • $\begingroup$ To be honest, I need to do what is shown: goo.gl/fHvMAb. $\endgroup$ – NoNewtoniano Oct 13 '15 at 8:30
  • $\begingroup$ Related: 39386. $\endgroup$ – dionys Oct 13 '15 at 9:00
  • $\begingroup$ At the time those pages you referred to were written, you did need to load a package to use Hue[] and the named colors; they have been built-in for quite a while, as noted in dionys's answer. $\endgroup$ – J. M. will be back soon Oct 13 '15 at 9:13
  • $\begingroup$ Thank you very much for the help! $\endgroup$ – NoNewtoniano Oct 13 '15 at 21:15
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The message Get::noopen is a warning indicating that your package was not loaded.

This particular package was useful in version 5.2 and earlier, but has been superseded by the functionality built into ColorData introduced in version 6. For newer versions of Mathematica the colors in the code you're using are available without loading anything extra.

Incidentally, the old colors are still accessible:

ColorData["Legacy", "ColorNames"]
(*{"AliceBlue", "AlizarinCrimson", ... ,"YellowOchre", "Zinc"}*)

ColorData["Legacy", "Zinc"] // FullForm
(*RGBColor[0.990005`,0.97`,1.`]*)

Module[{g, u}, g[z_] := 1/(5 z^4 + 26 z^2 + 5);
 u[x_, y_] := Re@g[x + I y];
 Plot3D[u[x, y], {x, -3, 3}, {y, -3, 3}, PlotPoints -> 25, 
  PlotRange -> {{-3, 3}, {-3, 3}, {-0.05, 0.4}}, 
  AxesLabel -> {"x", "y", ""}, ColorFunction -> Hue]]

enter image description here

Also, the legacy code for the Colors package is still available through the Wolfram library archive (MathSource).

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  • $\begingroup$ "Colors.m" should be available, but the link to the file wasn't working when I tested it. $\endgroup$ – dionys Oct 13 '15 at 9:25

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