There are some patterns that have emerged in Super Sentai with the colors for the core team and how many members start with. This started in the last decade and not in the 90's. That is why I am not comparing the nineties. I am using the Super Sentai names because they are the ones that started and are one year apart and not like Power Rangers that now differ from two years to three years. Most noticed that 2002 Hurricanger and 2003 Abaranger started with 3 members, 2004-2006 stuck to main 5, then 2007 Gekiranger started with 3 again and Go-Onger technically started with three. 2009-2011 stuck again to main 5 and normal colors. Then 2012 Go-Busters started with three.
2000 and 2010
Timeranger and Goseiger
Timeranger started with 5 and Goseiger started with 5. Timeranger has Red-Blue-Yellow-Pink-Green while Goseiger had Red-Blue-Yellow-Pink-Black. Timeranger had a Red Sixth Ranger which hasn't happened since. Goseiger had a Silver Sixth. The last team that was Red-Blue-Yellow-Pink-Black-Silver was in 2006 with Boukenger.
2001 and 2011
Gaoranger and Gokaiger
Gaoranger started with 5 and Gokaiger started with 5, both ended with 6. Both had Silver Sixth Rangers. Gaoranger has Red-Blue-Yellow-White-Black while Gokaiger has Red-Blue-Yellow-Pink-Green. Funny thing is Gokaiger has more similar colors with Timeranger. Goseiger would have had similar colors to Gaoranger if it wasn't for GaoWhite.
2002 and 2012
Hurricanger and Go-Busters
Both series start with 3 and both cause unconventional color choices in different orders. Hurricanger also has this in common with Gekiranger. Hurricanger ended with 6 while Go-Busters ended with 5. I am not counting Black Puma and Green Hippo from Go-Busters special. Hurricanger has Red-Blue-Yellow-Crimson-Navy-Green and Go-Busters had Red-Blue-Yellow-Gold-Silver.
2003 and 2013
Abaranger and Kyoryuger
Both are Dinosaur-based but color-wise, they differ. Other than obvious dino differences such as Pterandon going from Yellow to Gold and Triceratops going from Blue to Pink. Also every color under the sun except for Yellow and Orange. Abaranger started with 3 and ended with 5. Kyoryuger started with 5 and eventually ballooned to 10 (even though we've seen so many variations ending in 20 warriors). Abaranger had Red-Blue-Yellow-Black-White and Kyoryuger with Red-Blue-Pink-Green-Black-Gold.
2004 and 2014
Dekaranger and Tokkyuger
Dekaranger started with 5, Tokkyuger as well, Dekaranger ended with 8 (technically we saw 10) and Tokkyuger is rumored to have 9. Both started with the traditional Red-Blue-Yellow-Pink-Green.