You can use black without hesitation - Jetstream SNOOPY The knocking part is black ink, so you can use black ink right away. The body is light blue. Refill diameter: 0.5mm Colors: Black, Red, Blue I have used it several times at work and at home. There are no noticeable stains, but it is a used item. * The memo pad on the backing card is not included. Will be simply packaged.