a light skin (in the sense of "fair complexion") is 'peau claire' in French.
Beautiful skin in French is "Belle Peau" :)
To say "light" as in a light color in French, you can use the word "clair."
la peau
"Piel clara" = light colored skin "Caucásico" = Caucasian
In French, "light blue" is translated as "bleu clair."
Lampe
leger = light
The English phrase, "writing with light", is "écrire avec la lumière" in French.
pâleur de la peau
Fonction de la peau.
Ampoule - light bulb.
Feu vert