I love the design, le puedes cambiar un poco la forma y usar colores como el verde viejo, beige, bordo, celste bien claro, usa esos colores, cambiame el color del fondo por un beige

(bad-image-v2-39000, bad_prompt_version2, bad-hands-5, EasyNegative, NG_DeepNegative_V1_4T, bad-artist-anime:0.7),(worst quality, low quality:1.3), (depth of field, blurry:1.2), (greyscale, monochrome:1.1), nose, cropped, lowres, text, jpeg artifacts, signature, watermark, username, blurry, artist name, trademark, watermark, title, (tan, muscular, loli, petite, child, infant, toddlers, chibi, sd character:1.1), multiple view, Reference sheet, long neck