It's rather limiting to claim a favorite color. After all, tastes change and so do moods. When I am asked the question, though, my answer is green. I suppose it has something to do with its calming effects, the reminder of fresh cut grass, and of course, green tea. In fact, the first thing I watched on TV the day my dad bought our first color TV (I grew up in the 80's; this was not so unusual back then) was a baseball game. The color of the field grass: unforgettable.
Still, I have leaned towards purple in many other ways. The majority of the clothes in my wardrobe are purple, have a kind of purple in them, or go with purple. There is no season for purple: violet, lavender, lilac, it's always fitting. Most colors go with purple: green (!), some blues, red, pink - purple is the new (and more cheerful) black. It's associated with royalty, but belongs to everyone. Purple hats are awesome!
Even better, there's no holiday (at least in the US) associated with purple. In this color, no one asks me, "Oh, is it St. Patrick's day already?" or any other banal comment like this.
Tea itself is not purple colored, but teapots and cups are often painted with violets...so it accompanies tea.
Nice thoughts to dwell on in the gray winter.