How did Frans Hals use color to create the forms in his portraits?

Frans Hals utilized color as a fundamental tool to structure forms within his portraits, a technique that distinguished him from many of his 17th-century contemporaries. Rather than relying on the traditional, slow process of preparatory drawings and elaborate finishes, Hals often began directly on the canvas using quick, loose strokes of bright color.1

These spontaneous, vibrant applications of paint served to suggest rather than strictly enclose form, effectively capturing the vitality and movement of his subjects. While his early works were characterized by a "colourful blare" and a jovial spirit, his approach evolved over time. In his later years, as his palette became less lustrous, he demonstrated a masterful ability to work with a broad range of blacks and whites, which he found sufficient to convey his artistic vision. Throughout his career, this unique use of color remained highly expressive, allowing him to achieve a striking immediacy in his character portrayals.12