A background should sit behind the text, not in place of it. This paragraph lies on the tile at its true scale — if it reads without effort, the tile can go under content.
Vivid rainbow blobs of magenta, red, orange, yellow and green sit on a bright blue ground, forming rounded checker-like cells. Small four-armed star accents and leaf-shaped sprigs appear at the cell junctions, and the repeat creates a steady diagonal rhythm across the grid.
CC0 — use it for anything, no attribution needed.