Blue's Clues & You! is the third series in the Blue's Clues franchise. The second series, Blue's Room, was a spin-off of the original series, so it took place in the same continuity. However, it's been very hard to tell if Blue's Clues & You! takes place in that continuity. A lot of the show's aspects seem to indicate that it's a reboot, but other aspects make the show look like a sequel.

Reasons why Blue's Clues & You! could be a considered a reboot:

Blue and Magenta appear to be the same age that they were in the original series. The talking objects, except for Paprika and Cinnamon, seem to be the same age that they were in the original series, too.

Several episodes are word-for-word remakes of episodes from the original series. That means that several events from the original series, such as Magenta getting glasses and Periwinkle moving to the neighborhood, are repeated.

Blue's younger brother, Sprinkles, doesn't appear. If this show took place in the same continuity as the original series, it's odd that Blue wouldn't be looking after her brother. A scene in Blue's Big Musical Movie implies that Sprinkles is now a critic. However, if Sprinkles is Blue's younger brother in this show's continuity, it doesn't make sense that he's never brought up in the series.

There are references to Blue's Room in the new series, but Blue having a room where she can walk and talk like a human is never brought up. If the new series takes place in the same continuity as the original series and Blue's Room, it's odd that Blue is never shown going to her room.

Reasons why Blue's Clues & You! could be a considered a sequel:

Paprika and Cinnamon have both aged. Paprika, who was a kid in the last season of the original series, is a teenager in the new series. Cinnamon, who was a toddler, is now a kid.

Steve and Joe have also aged and have gotten jobs. Also, the fact that they used to play Blue's Clues is brought up. In fact, the first episode of the new series has Steve and Joe teaching Josh how to play Blue's Clues. Steve and Joe's appearances tend to have lots of hints that the new series is a sequel that takes place years after the original series rather than being in a new continuity.

In the first episode of the original series, it's established that Josh has never played Blue's Clues before. Since Blue always leaves clues to find, Josh must have not been living at the house for very long. That would imply that the new series takes place shortly after Joe moved out to run the Present Store.

So, is Blue's Clues & You! a reboot or a sequel? That's hard to answer, because the show remakes stories from the original series but it also references the original series in a way that suggests that it's canon to the new series.

There are two possibilities:

One possibility is that Blue's Clues & You! takes place in a new continuity where Steve and Joe happen to be Blue's former guardians.

The other possibility is that Blue's Clues & You! takes place in the same continuity as the original series, but for unknown reasons, events from the original series are being repeated.