Blue's Clues followed the everyday adventures of a man named Steve and his mischievous puppy, Blue. Every episode of the show followed a set pattern that began with Steve outlining to the audience a simple mystery that Blue had created for them to solve. Throughout the show, Steve would work through the mystery by discovering the three clues left by Blue, relying on the help of the viewers. Blue's clues were always identified with small blue paw prints. Each show would focus on one overarching theme, such as a word or concept, and would explore that theme through several games, puzzles and vignettes set throughout the episode. All episodes would finish with Steve sitting in the "Thinking Chair" to analyze the clues he and the audience had discovered and coming up with the answer to the mystery.
Blue's Clues was filmed entirely in front of a green screen and the set, props and most of the characters were added in using computer imaging later. The character of Steve, played by actor Steve Burns, was the only live-action member of the cast. The visual design of Blue's Clues was created to emulate a child's story book, and therefore focused on vibrant colors, eccentric patterns and exaggerated sizes, such as the huge "Thinking Chair." To further the idea of the story book, all progressive movement moved left to right to imitate the eye's movement during reading. The computer-graphics team at Nickelodeon also worked to make the visual design of the show multidimensional and used a variety of items, ranging from cloth swatches to pipe cleaners, to provide a variety of textures and aesthetics to the sets.
Blue's Clues was conceptualized in 1993 by Nickelodeon producers Todd Kessler, Angela Santomero and Traci Paige Johnson. Their goal was to produce a worthwhile children's program built around the results of early childhood education studies done at the University of Massachusetts through the 1980s. Based on the research, the producers wanted to create a show that encouraged learning through participation, helped develop problem solving skills, optimized a preschooler's attention span and gave preschoolers a sense of control and value. They achieved this by incorporating several novel learning techniques into the episodes, including visual and audio repetition as well as structured pauses meant to give children time to think and process what they were learning.
By the early 2000s, Blue's Clues was one of the most popular preschool shows on television, and was rivaled only by Sesame Street, which was in its third decade of production. Steve Burns, the actor who played the character of Steve, left the show in 2002 and was replaced by Donovan Patton. Patton did not replace Burns as the character of Steve, and was instead introduced to viewers as Steve's friend, Joe. This was done to avoid confusion among the viewers, but confusion persisted as Patton and Burns looked extremely similar. In 2004, the producers of Blue's Clues created a spin-off series based on the original show called Blue's Room, which focused entirely on the adventures of Blue.
In spite of all its critical acclaim, Blue's Clues was not free from controversy. When Steve Burns left Blue's Clues in 2002 to focus on his singing career, an urban legend developed that Burns had actually died from a drug overdose. This rumor was heightened by the resemblance between Burns and Patton, and many suspected producers were trying to cover up Burns's death for the viewers. The story persisted even after Burns and the producers made several public appearances to dispel them.