Before you go "wtf?" on me, here's some backstory

In 1987 or so, the popular stationary goods company, Seika, went to Animation company Studio Pierrot and asked to collaborate and create a new character/brand for their products. 
Pierrot answered with Magical Designer Fashion Lala 

A "story" of 10 year old Miho who uses a magic pen to transform herself into an adult who wears clothes she designs. The idea was that children could send Seika their ideas for clothes and the winning designs would make it into the next coloring book. 
Studio Pierrot even created their now lovable OVA trainwreck "Harbor Light Story~From Fashion Lala" in 1988 to promote sales.

It worked like a charm and Then Seika came up with the idea to make more similar franchises. and went to other animation studios to create brands. From there we got a whole late 80s-early 90s era of Coloring book Magical Girls

Toei Animation: 
Omajinai Idol Lyrical Lena

Lena comes from the year 2088 and gets scouted to be an idol in Harajuku. She uses her pendant to change outfits.

Ashi Productions (Studio Reed)
Hoshi no Duet Funny Twin




Yu (blue hair) and Ai (pink hair) come from outer space to look for a stone on Earth and they become idols for some reason and make friends. Oh and they can use ESP.

Studio Pierrot
Otenba Majo Twilight Mary

Lil, a magical princess came to the human world to study.Transforms into an older form, Mari, and becomes an idol.

Mahou no Stage Idol Coco


Coco Kitajima meets two fairies and they each give her the power to become two adults - Nana (blonde - for singing) and Sara (blue - for modeling). As you can guess, she uses the power to become an idol.

Also her mascots are mushrooms and thats adorable.

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I have a small Fashion Lala collection myself and they're really cute and tacky as you can imagine an 80s fashion coloring book can be. But I love them dearly and really wish their respected animation houses used them for a show.