Waccha PriMagi!

similar in a way by using choords aka attires, during performances.  

Both Aikatsu and Pretty Rhythm (the main series of waccha primagi) often have a lot of similarities, so if you like one it's quite likely you'll like both. Both have wholesome idol dynamics, magic elements, cute girls and CGI performance with the music actually being sang by the voice actor of the character (something that doesn't happen in every idol anime where sometimes seiyuu and singer are two different people). This makes it feel more realistic and close to the actual jpop scene (some people are against this so ymmv). Both also have a focus on duo performances and the idea of a best friend/partner 

With similar friendship dynamics - neither of their central pairings see eye to eye almost ever - to the hidden corportation of creepy, the competitive nature of nearly everyone (even when unneeded), the insertion of often totally random musical sections and with magical otherworlds in the mix, you get the point, there's a lot of similarities between these two series. 

Both share a similar idol modality, with performance and dance in CGI animation, magical elements to make beautiful costumes, and academic challenges to overcome.