Hmmm...
Falrewn: Beautiful and brash immortals who change with the seasons.
Let's cut the current dynamic then and make them a people that are predominantly violet-skinned, but with some leaning towards blue and some leaning towards red. Their hair comes in both green and brown. Children start out as creamy white and bald with eye colour matching the way their skin will eventually turn out. All falrewn, even children, change with the seasons, becoming less vital but all less foolish in Autumn and Winter.
Culturally, instead of having different clans, we can perhaps say that falrewn are extremely territorial: intruders are to be excised like weeds. This extends even to falrewn communities. While they have public spaces in which to be creative and mingle, to enter the home of a falrewn means death, even for their friends (though of course a falrewn wound never enter the home of a falrewn friend). And despite a love of gardening, falrewn are almost never druids, instead relying on mundane skills and their smarts.
+2 Str, +2 Int, -2 Wis (might help explain why they do not always flourish despite being long lived)
Acid Resistance 5
Stubborn
Hatred (Elf and Reptilian)
Share Memory 1/day
Low-light Vision
+2 to Profession (Gardener)
Hold Breath
Not sure how I would handle it in 4E. That game is not my area of expertise. But it might be something like:
+2 Str, +2 Int
Size: Medium
Speed: 6 Squares
Vision: Low-light
Languages: Common, Falrewn
Skill Bonuses: +2 Bluff, +2 Diplomacy
+N Racial Bonus to Saving Throws vs. Charms
Acid Resistance 5 + 1/2 Level
? Encounter Power Based on Memory