Design a mixed-media collage featuring a close-up portrait of a female face that expresses serenity. Use a vibrant color palette of teal, magenta, and sunny yellow to evoke a feeling of tranquility. Surround her face with hand-drawn geometric shapes, including triangles and circles, seamlessly blending with abstract fluid shapes that flow into the background. Incorporate textured layers such as fabric swatches and patterned papers to add depth and interest to the composition. The digital illustration style should combine realistic facial features with whimsical elements, resulting in a colorful and harmonious piece that invites contemplation and peace.