I like incandescent C-9s also. I also like the older bulbs which seem to be brighter than the newer ones and the paint lasts longer. Indoors I have incandescent mufti-colored minatures around the windows and single color on the trees.
Both. I intertwine both multi colored and white lights. Makes my tree brighter.
Both. I grew up with a multi-color lighted tree and a white lighted tree. The white one was special, first in that it had lights that actually twinkled, randomly on and off, until our last string of twinklers died. By that time, my mother had started another theme for that tree of using all clear glass or crystal ornaments.
I managed to find a couple of strings of colored twinkle lights so my tree has colored lights, some of which twinkle.
Now that my parents have passed away, I’ve inherited most of the glass ornaments (I gave them one every year) I could do a second tree. But I don’t really have room for it. I am thinking I might get a few deciduous branches, spray paint them and put them in a tall, weighted vase and hang the glass ornaments there. I thought they always looked lost on the white-light tree. But I will only consider adding white lights to the new arrangement. The glass would lose something with the colored lights.
White if you drink wine.
Multi-colored if you drink beer.
Why do your drink preferences matter?
On a tree, I prefer monochrome lights, color depends on what you’re shooting for with the rest of the decorations. This year it’s white, but in past years I’ve done all red and all blue.
For the outside of the house, as multicolored as possible. 
I also have a mad passion for lights from my youth - bubble lights! But I haven’t had/seen any in many, many years… 
My mother and I had the same fight pretty much every year until I finally moved out.
Mother: “There’s enough color on the tree with the ornaments”
Me: “You can’t see the ornaments at night with the lights out”
What my tree looks like now. There’s a reason only the top half has lights; it’s the only part of the tree that can be seen from outside the house (because it’s on the side of a hill and there’s a balcony on the other side of the glass door).
At my most recent trip to the hardware store, I noticed that they now sell lights that you can switch between white and multi-colored.
I like single colored strands. I like white, but also blue and pink.
Definitely multicolored. It’s prettier, more festive, and it’s what I remember everyone using in my childhood.
White light is boring; you see it every day.
Unfortunately colored lights as Christmas decorations in stores and restaurants seem pretty much dead in the DC area. In the Tysons Corner mall, there are only two stores (out of some 200) which have colored lights. Even all the displays in the seasonal Christmas decorations store have white lights, the first time that has happened (there used to be at least one token tree festooned with multicolored lights.)
White.
Do you remember that house on Abbott Loop, a mile or so up from Lake Otis (going toward Service)? The ones that outlined their entire house and their long driveway in blue lights and outlined the horsehead on their barn in blue too? One of my favorite looks.
I have a really beautiful artificial tree that has 700 steady-on white lights. To that I’ve added four strings of 100 randomly-blinking white lights. That adds up to 1100 lights. Very impressive-looking. And the cats like to lie under it when the lights are on.
I do appreciate multi-colored lights too, but not if they include white.
It depends on how the tree is decorated. If the tree has random source ornaments, then usually multicolored lights look better. If the tree has a color scheme, (mauve ornaments with silver ribbons, for instance), then single color lights will usually look better.
Please note that when it comes to bright shiny things, my tastes are remarkably like those of wizzards and magpies…that is, I believe in good taste and self-restraint.