It’s a problem, but a pretty funny one, to me. Mine does the same thing, startup is full rainbow, then it settles.

At least most of that can be turned off in settings somewhere.

Bought a neat closed-loop watercooling cpu heatsink that has a whole dang programmable screen on it if I pay a monthly thing, or solid colors if I don’t. defaults to cycling through the rainbow. But it has an off mode, so I’m A-OK with none of that.

You can go into your account and under two-step, generate a one-time code. Store that code somewhere secure, like a note in your password manager if you trust it with both steps, and you can do it.

Pretty sure Google authenticator will have something equivalent but likely more secure, but haven’t used it.