I usually sketch in a shade of pink or orange. No particular reason. Sometimes saturated red can be harsh on my eyes although.
Pretty simple question. What colour do you sketch with and why? This is assuming you're going to line the sketch and not use it as lineart
I use to sketch in red but a friend of mine is colour blind, so they see red as yellow. After they told me that I started to sketch in light blue, and I've been doing that ever since
I'll usually sketch with a grey-red or a grey-blue. I prefer to line in black right away but when it comes to making the lineart I have trouble differentiating a low opacity black line from my actual lines. Having either red or blue at 40-60% grey really helps with that.
As for why it's red or blue in particular, well I just like those two colours and find them easiest to look at when linearting! I have tried other hues out of curiosity but I just keep going back to blue or red.
Usually I use black, brown or blue! Sometimes my 2nd sketch is red to contrast with the blue haha-
But tbh most of the time I just sketch with my last used colour in SAI, unless said colour isn't dark enough
I usually use either blue or red or purple to sketch with, usually when darker but sometimes as its regular shade too owo.
Edit: I also can take the hair or eye color of an oc, or the main color from their palette to sketch with too xD
Usually a light blue or teal, but it can be other colors if I feel like it, and if I need multiple sketch layers (different characters or clothing layers or whatever I need separate), they'll be different colors, like blue, pink, purple, green.
edit: and even if I do use the cleaned-up sketch as the lines, I just throw a black or low-saturation darker color over them as a clipping layer
Just plain black! But if I were to lineart over it (at least for digital sketch) I just fill the sketch's color (using SAI's clipping group) with red and lower the opacity
Black or blue, I guess. When inking or w/e I drop the opacity of the layer(s) so it doesn't matter in the long run.
Mainly Purple! But sometimes I use warm browns and red! I don't really have a good reason why I used those colors really. I think purple looks more pleasing to me hah