Harlequin Callista Wallpaper. Callista is a collection teamed with Clarissa Hulse. Callista means 'most beautiful' in Ancient Greek, we have created an enticing and entrancing collection of wallpaper, woven fabrics and printed silks. The delightful wallpaper collection makes an impact both individually and when used in conjunction with the beautiful fabrics. Clarissa's love for colour is reflected in the Callista collection, where rich emerald, moss and forest greens are introduced to compliment her trademark shades of kingfisher, neon pink, paprika, slate, turmeric and zinc.