Oh yes. It a special type of pencil for sketching/drafting. The one that I’m using is for mechanical pencils, there are also wooden blue pencils too. It’s quite expensive compare to ordinary pencils, for me it was like about 1-2x the price. You can find these in large stationary stores or stores that sells art supplies.
Blue pencils are recommended for those who can’t kept their sketch clean/ always smudged the pencil lead on their paper. The good thing about blue pencil is that after you do the inking, even if you don’t erase it, the colour will fade away almost entirely when expose to air and light. It doesn’t smudge too.
A bad thing about it is that the sketch you did can’t or hard to kept permanently since the colour fades away after certain amount of time.
Fyi there’s other colours as well, purple is deeper in colour and light blue is the lightest one.