When was the first time Madonna went fully blond?

[androiduser 2,615]

I just realized I can't figure out when Madonna premiered fully blond hair? In the early 80's she had streaks and highlights, but she was mostly light brown with blond highlights, but on the cover of the first album, she had platinum hair.... Was this the first time? It doesn't seem like she held the platinum look for long back then?

[Roland Barthes 5,953]

Right before shooting the first album cover, apparently it was a dare with Martin Burgoyne whom went platinum too at the same time.