Dyed indigo is a type of fabric dyeing process that involves adding a blue-violet hue to fabrics. The term 'dyed indigo' is derived from the plant species Indigofera tinctoria, which is native to India and other tropical regions. The process of dyeing fabrics with indigo dates back to ancient times and has been used to create vibrant colors in clothing, textiles, and other materials. The crossword solution 'blued' is a reference to this process, as it is a synonym for the term 'dyed indigo.'