Consistently yes but it goes back even further:
Boukenger - Silver
Magiranger - Gold
Gaoranger - Silver

In the last 10 years (starting with Abaranger) there have been
5 Gold Rangers (counting DekaGold)
5 Silver Rangers
5 White Rangers (I'm including DekaBreak, DekaSwan & MajiMother)

I think we're running out of bright colors here folks.

If gold turns out to be the bird guy and another human ranger shows up later, iw would perfactly fine with it. Look on the bright side al lest its not a phone

Why can't we have a sixth ranger be Pink. Why I ask you?!

That's because a Pink Ranger is likely necessarily a female Ranger by color, and lone female sixth Rangers are still considered too risky.

Pink is part of main 5

You forgot MegaSilver.

Really excited for KyoryuGold's Zord, hopefully it'll be pretty large and have it's own Megazord form like Go-Buster Beet's BC-04 and then be able to combine with the other auxiliary zords into another Megazord form like GaoIcaru. Hoping that it'll be more like Go-Buster's zord-combination style instead of simple limb swapping.