I just noticed that in the Japanese set it's impossible to recolour the flowers in the longer hair. Trying to recolour gives you an 'invalid style' error. This means the creator used the wrong textures.
If it was *meant* to be un-recolourable, you would get the message 'style cannot be changed' without the entire CASt tool locking up.
The same thing happens with the long-stem signs from the Ambitions EP. You can select the presets with the different pictures, but you can't change the textures for that same reason.