It is a complex issue here in french-speaking countries. As for as the colonies are concerned, the British could have done the same thing I suppose, since Jamaica was part of the United Kingdom, which probably explains why Barnes played for England.
France is an interesting example. They were the first European nation to radically change how nationality was obtained; jus soli (birth right in land), instead of the Germanic jus sanguinis (blood). It wasn't until after the Victorian times that Britain followed suit. France offered nationality to the Africans, Jews and other immigrants, mostly those who fought in the wars for them on the condition they assimilated and gave up their 'roots'. It hasn't been implemented as successfully as the government hoped it would, hence the debates about national identity -- what does being French actually mean? Then after the Second World War you had the mass immigration influx, beurs (like Zidane's parents) moving to Marseille, et al.
I do think France recognised and adapted to the multicultural, globalised football playing field. Immigration influenced the national team, bringing flair, unlike England who continue to have this Anglo Saxon way of thinking (see Wilshere's up and at em comments yesterday). Incidentally, I would argue it wasn't until Wenger's appointment and first successes at Arsenal that the Premier League had shaken that off -- they became less insular. Arsenal scouted, purchased and integrated talent from abroad on big scale, now it is a common trait with all 20 teams.
Well, I'm half joking. Identity is a difficult thing. If you've been bullied for much of your life for being Black/Asian/(is Arab acceptable?), presumably it's difficult to feel British.
It can be. Going back to France, Le Pen described the team as "artificial", did he not? He ironically claimed Zidane was an exception to the 'foreign' tag, presumably as he didn't want to take on someone with great power.
The WC win was overplayed by the French media as if multiculturalism never existed in France before 1998. What it did was confounded the country into a state of confusion. French Arabs booed the national anthem when France played Algeria in 2001. The same who celebrated the WC win because it offered hope to them. Does that suggest a united national identity, one who share the same values? France at heart is a republic; I guess mass immigration challenged that in ways football never imagined. Soon after you had Le Pen's rise because of voter apathy and later the riots.