updated alias and corrected python package (#6520)

plugins/colorize/colorize.plugin.zsh

@@ -3,11 +3,12 @@
 # If no highlighting method supported for given extension then it tries 
 # guess it by looking for file content.
 
-alias colorize='colorize_via_pygmentize'
+#easier alias to use plugin
+alias ccat='colorize_via_pygmentize'
 
 colorize_via_pygmentize() {
     if [ ! -x "$(which pygmentize)" ]; then
-        echo "package \'pygmentize\' is not installed!"
+        echo "package \'Pygments\' is not installed!"
         return -1
     fi