Fountain pen lovers: how do you manage ink colors in future planning?

I love using fountain pens and switching inks often, but I’m curious how others handle ink choices, especially for future planning in the monthly spreads. For my weeklies, I fill them in every Sunday based on my monthlies and digital agenda, so ink color isn’t a big issue there.

But my monthlies end up looking like a rainbow, depending on which ink was in my pen at the time.

What do you guys do?

Do you use a different pen or ink just for the monthlies? Do you avoid fountain pens for planning altogether (and only use them for, for example, journaling)? Do you stick to one ink per year (I can’t imagine doing that myself 😅)? Or do you just embrace the chaos?

Would love to hear how other fountain pen lovers approach this!