The opening intro is what starts every episode.
We fade to the Blue's Clues title book, which is piled on top of other books, including The Very Hungry Caterpillar, Goodnight Moon, Corduroy, The Little House, Madeline, and The Runaway Bunny. The cover opens to reveal Blue and Steve's house. Steve pops out the window on the right. He says "hi" to the viewer. He then asks where Blue is, and she bounces out from behind the flowers. She then kicks her ball with her nose and skips towards the house as the ball bounces off of Mailbox. Mr. Salt, Mrs. Pepper, Slippery & Tickety are shown in the windows, while Shovel & Pail appear near the house. Blue then goes through the doorway, as the doorbell rings and Steve opens it up, and the episode begins. Starting with What Does Blue Want To Make, Blue hides behind the house.
Same as the Season 1 intro, Blue hid behind her ball from the episodes Blue's ABCs, Math and Blue's Birthday. Most Season 2 episodes have Blue hiding behind Mailbox. Only a few episodes had Blue hide behind the flowers. In Blue's Surprise At 2'o Clock and What Did Blue See?, there's a version in which the viewers don't say "There she is!".
Early season three episodes are exactly the same. However, the flower hiding place is used rarely. Most of these episodes have the usual Mailbox hiding place. Starting with Draw Along With Blue, we now cut to the Blue's Clues title book.
Starting with Inventions, The Wrong Shirt and Words Periwinkle is shown briefly jumping onto the tire swing. And Blue returns to her usual flowers hiding place. Magenta Gets Glasses, Blue's Collection, Café Blue, Shy, Environments and Stormy Weather.
This time, a new shot of the Blue's Clues house is shown with Magenta's and Periwinkle's houses nearby. Also, Shovel and Pail pass by Blue and say hi to her after she bounces the ball to Mailbox. Blue also passes by Periwinkle bouncing on the ball. Magenta is pulling a wagon with the ball in it. The windows show the living room's walls other than purple walls.
If you look closely, you can see Paprika in the window with Mr. Salt & Mrs. Pepper.
Seasons 5 & 6
The opening intro is changed completely into a theme song featuring most of the main characters singing along with a few recurring characters. Also, the book sequence has changed with the title book shown on a bookshelf. Blue skips over, takes it out, opens it (to reveal that it is a pop up book of the house) & bounces into it as the book turns into cartoon life. Various characters appear like Periwinkle, Magenta, Shovel, Pail, etc. The characters play various musical instruments. Then, Mr. Salt holds a flag with the title written on the right and a descriptive picture is shown on the far left. After that, Blue goes into the dog flap.
It has been changed again with the book being shown in Blue's Room. Moona appears and turns the puppet Blue into the animated Blue, before she bounces in the book and then the rest of the introduction is the same one used from season 5.