Why Red?

<deleted> has this to do with communism?

Socialism

The people's flag is deepest red,It shrouded oft our martyr'd deadAnd ere their limbs grew stiff and cold,Their hearts' blood dyed its ev'ry fold. Then raise the scarlet standard high,Within its shade we'll live and die,Though cowards flinch and traitors sneer,We'll keep the red flag flying here.^{http://en.wikipedia.org/wiki/Red_flag#cite_note-12}

Which country is harbouring Thaksin?

What colour is represented by communism?

There are reports in the media that former communist supporters and deposed government officials have taken up sides with the "red shirts'

Since the Paris Commune of 1871 (and possibly since 1848) red has been the colour associated with socialism (not just communism) in Europe, Asia, and beyond.

A classless society would sure appeal to those who are leading this current revolt against the Thai Elite Government. In their eyes Thaksin is one of them.

Isn't the colour red associated with the US Republican party?

It's the colour of strength and solidarity as it represents the blood of the people. Whereas the yellows sought to associate themselves with the monarchy by adopting (hijacking?)that colour.