Amazon.com: BIC 4 Color Ballpoint Pen, Medium Point (1.0mm), 4 Colors in 1 Set of Multicolor Pens, 3-Count Pack of Refillable Pens for Journaling and Organizing (Pen barrel color may vary) :
Amazon.com : BIC 2 or 4 Colour Pen Refills - Black (Box of 50) : Office Products
BIC 2 or 4 Colour Pen Refills - Blue (Box of 50) : Amazon.co.uk: Stationery & Office Supplies
BIC 4-Colour Multipen Refill
Buy Bic 4 Colours Counter Pen Blue Ink 1 mm Tip Retractable Ballpoint Pen | Avansas®