Overhead Line Insulators

You like to see it in pink color. Why did you think so?

It may be the color of the ceramic(clay) used.

My guess is that:

A) Brown is inexpensive

B) Since the underlying porcelain is white, brown would make it easy to visually detect cracks or damage to the insulators.

Why not black?

High-voltage porcelain insulators are made from clay, quartz or alumina and feldspar, and are covered with a smooth glaze to shed dirt. The design of insulators often includes deep grooves, or sheds, that provides increased arc-lengths. Insulators made from porcelain rich in alumina are used where high mechanical strength is a criterion.

It looks like from what I can find out, to give the required electrical properties the glaze ends up brown in colour

It seems that if you want a semi-conducting glaze it will most likely be white.
What surprised me while looking at various insulators there's a company making them out of varnished wood!!!!

like this?

lol......

Your statement is not true.

I have used transparent insulators made of glass and grey color porcelain insulators besides the brown one (Epoxy and fiber glass insulators are there as well).

When glass insulators were developed some one conducted tests to prove that dust accumulates more easily on glass which will eventually cause spark over.

If you have reservations with respect to the conventional brown color, go ahead and prove it that brown glazed surface is inferior to any other color glazing.

Provided that you can develop a compelling thesis, We all promise to name the changed color insulator as " spuradbhat insulator"

I meant, why, in general, most of the overhead line insulators are brown in colour?

Is there any specific reason for using this colour?

There is absolutely no problem that there are insulators which have colour other than brown.

Maybe in your area the predominant color available from insulator manufacturers is brown. Most of the ones used by US utilities these days are gray (ANSI 70?). The color really doesn't affect their function, and brown is a common glaze color for pottery/porcelain products. See this link for some other colors used in the past, and some history of glass & porcelain insulators:

http://www.insulators.info/porcelain/color.htm