The first color I remember drooling over was a yellow color crayon. I used to scribble in one spot over and over and over again, pressing as hard as I could, trying to put on paper the magical world I felt emanated from the crayon. I must have been about 3.
What a fickle kid I was. I quickly forgot yellow and went on to other exciting colors: green, blue, purple, adolescent red. Billions of a-hahs later I find I have once again attacked the yellow question. I can't say that I love yellow as I did back then, but I do find it inspires edgy stories not easily experienced, but well worth traveling into.