Pick two colors and a blend mode (multiply, screen, overlay, and more), and the tool computes and previews the blended result.
Formulas that combine a base and blend color per channel — the same math Photoshop and CSS mix-blend-mode use for layers.
Multiply darkens (channels multiplied, so white keeps the base and black forces black); screen lightens (the inverse, so black keeps the base).
Yes — overlay uses the base color to decide between multiply and screen, so swapping base and blend can change the result.