Differences in annual holiday gifts?

[Ireland]

I happened to log on today for a few minutes and was going through my stuff to see what I had. I noticed that the fireworks from last year differ from the most recent one. One (4th of July 2009) is a blood/crimson red and the older version is a glowing-neon red, do gifts slightly alter every year? Here's a picture of it, but it's somewhat difficult to see it in the picture. It's much more visible in the game.