Why Silver Color in Power Transmission ?

They are galvanized to avoid the need for painting. Nobody wants to shut down a transmission or distribution substation in order to prep and paint it.

Insulators?

it makes the red stuff stand out more

Although you didn't tell us, I'm going to guess that you are in an area where it's hot and the sun shines a lot. If so then the aluminized coating is there to reflect the sunlight and keep the equipment cooler than if it were painted in a dull dark color.

Silver color is nothing but galvanizing coating to withstand harsh outdoor environmental conditions for a longer period. However, as far as my observation goes it is generally the steel structures like poles etc., that are galvanized. Transformer and other equipment are properly painted in the assembly lines keeping in mind the challenges of outdoor installations.

They would look silly painted PINK!

One of the usual non corrosive and plenty metals in these equipments is GALVANIZED METAL which has a silvered color.

Thanks everyone... What I can conclude from this thread is Most of the electrical equipments made out of galvanished metal. So, they are in silver color. Also, it helps to reflect solar irradiation. So, they are not painting in silver color

The "silver color" is most likely galvanized paint (or galvanized metal). This is to (1) prevent corrosion in outdoor environment, and (2) provide a remarkable contrast to smoke and fire when they do fail and catch on fire.