# Having variables appear aqua in user defined function [duplicate]

In many of the inbuilt mathematica function, variables appear aqua like in:

However, when creating your own function, variables no longer have that green coloring and are instead colored like an undefined variable

Is there any way to define functions so that variables used in arguments like in the manner above can get the aqua syntax coloring?

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## marked as duplicate by Mike Honeychurch, acl, Mr.Wizard♦Jul 16 at 1:59

you can set this via the preferences panel, the options inspector or a stylesheet. All of these methods have been discussed on this site. –  Mike Honeychurch Jul 15 at 23:53
@MikeHoneychurch That has to due with changing the syntax highlight coloring itself. I am asking how to get variables used in arguments of user-defined functions to exhibit that syntax coloring. –  user2612743 Jul 16 at 0:08
ok. misunderstood. @acl has your answer –  Mike Honeychurch Jul 16 at 0:18
@MikeHoneychurch looks like a duplicate –  acl Jul 16 at 0:22

You can use SyntaxInformation. In this case,
SyntaxInformation[Lim] = {"ArgumentsPattern" -> {_, _, OptionsPattern[]},

I also have another function ImplicitPlot[p_, q_, r_] := ContourPlot[p, q, r] and I tried doing something similar: SyntaxInformation[ImplicitPlot] := {"ArgumentsPattern" -> {_, _, _, OptionsPattern[]}, "LocalVariables" -> {"Plot", {2, 3}}} but it's not working for this one... any idea why? –  user2612743 Jul 16 at 1:01
Do SyntaxInformation[implicitPlot] ={"ArgumentsPattern" -> {_, _, _, OptionsPattern[]}, "LocalVariables" -> {"Plot", {2, 3}}} and does work. Make sure you use Set (=) and not SetDelayed := ! I searched for an explanation of the difference and found this which, to my surprise, I wrote myself. –  acl Jul 16 at 9:58