Used to fix mistakes, I am often referred to as the colour I bleed. What am I?

The item in question is correction fluid, a ubiquitous office and school supply known for its ability to correct written or typed errors on paper. It is often colloquially referred to as "white-out," a nod to its most common color and its primary function of obscuring mistakes with an opaque, white liquid. The phrase "the color I bleed" cleverly refers to this characteristic white liquid that flows from its applicator onto the page, effectively making errors disappear.

This ingenious invention greatly simplified the process of rectifying mistakes, especially before the widespread adoption of word processors. Typists, for instance, could easily cover up a misstruck letter or word without having to retype an entire document. The fluid itself is typically composed of an opacifying agent, such as titanium dioxide, mixed with a solvent and various resins, which allows it to dry quickly and provide a smooth surface for new writing.

The concept of correction fluid was famously pioneered by Bette Nesmith Graham, a secretary who, in 1956, developed what would become "Liquid Paper" in her kitchen. Other brands, like "Wite-Out," emerged later, with the "Wite-Out WO-1 Erasing Liquid" being introduced in 1966. Early formulations were sometimes water-based, but later versions often incorporated solvent-based formulas for faster drying times, continually evolving to meet user needs.