Why HoldForm[] shows this expression in red in notebook?

*To*: mathgroup at smc.vnet.net*Subject*: [mg125041] Why HoldForm[] shows this expression in red in notebook?*From*: "Nasser M. Abbasi" <nma%12000.org at gtempaccount.com>*Date*: Sun, 19 Feb 2012 06:30:47 -0500 (EST)*Delivered-to*: l-mathgroup@mail-archive0.wolfram.com

foo[x_, v_] := Module[{z = v}, {x^z, Hold[x^z], HoldForm[x^z]} ]; Any one knows why the notebook shows the 'z' in the last term above in the red and but not the other z's? I am using V 8.04 on windows thanks --Nasser