What colour do you sketch with?

The main color I sketch with is grey, but I picked up this thing where you draw on a grey background when you do digital stuffs (mostly bc I draw pretty late) so I'm starting to sketch in white 

or if i'm lazy i'll just sketch in my last used color lol

reds for the construction
blues for the refining of the sketch and such o>o

i sketch in the character who I'm drawing's eye color, if not, i sketch in neon red.

I would always draw with the transparent bg on ps, with the grey and white squares,so I'd choose a colour randomly but it'd always be a dull, soft shade. For example, a light blue grey or a dirty green. The bright neon colours would hurt my eyes and I'd lose myself in the sketch itself so I'd always go with a softer colour, then make the opacity lower, and use the same colour for the second or third sketch if need be (as I usually did two+ sketches when doing traditional art, and it always ended up making my lineart very smooth and clean by the end of it) 

good ol obnoxious bright red..... sometimes i use blue for other stuff like backgrounds or other characters in the same pic

I usually just sketch in black or a warmer grey. Bright colors are harder for me to see as far as lines go so it's easier for me to have the darker color lines.

i sketch in black because recently ive just been cleaning up my sketches and finishing art that way instead of doing lineart. i later change the color to like a dark red or magenta and burn it so it looks nicer tho :}

if i actually have the desire to do lineart, i'll just drop the opacity on the black sketch layer

          I never sketch using a single color for the entire pic because I get confused really easily which line is supposed to be which part and ink incorrectly. So to cope with how my brain works, I both sketch different parts in different layers (sometime up to 4 or 5 layers) and with different colors. Here's an example;

          For the six figures, I sketched two on each layer, each layer with different color (brown/purple, magenta and green), the BG frame in orange and uniform in black. These layers are in multiply mode so when I want to focus on inking a certain part on a certain layer then I can just lower the opacity of other layers to make what I want to ink stand out.

I use to sketch with blue since it's my favorite color. But I ended up switching to purple. I don't really remember why though

Usually dark blue or brown but it really depends on where it stops when i randomly spin the wheel

I use whatever I last used, although once I start lines i tend to change the color to something lighter if it was dark.

I sketch with either a light blue or red. Nothing too saturated. I don't really favor one over the other, it's just whichever one I'm feeling in that moment. But I use one of these mostly because it's easier for me to tell the lineart from the sketch.