I used these in a duel in a RP for a girl

Princess Red **
Type/Warrior ATT/Light
ATK:500 DEF:500
Effect: Select one "Royal Contrast" from your deck and add it to your hand when this monster is summoned to the field, then shuffle your deck.

Princess Blue **
Type/Warrior ATT/Light
ATK:500 DEF:500
Effect: Select one "Royal Contrast" from your deck and add it to your hand when this monster is summoned to the field, then shuffle your deck.

Princess Yellow **
Type/Warrior ATT/Light
ATK:500 DEF:500
Effect: Select one "Royal Contrast" from your deck and add it to your hand when this monster is summoned to the field, then shuffle your deck.

Royal Contrast
Spell
Effect: You can only activate this when you have two of either "Princess Red", "Princess Blue", or "Princess Yellow" face-up on your side of the field. Offer two of them, and if you offered "Princess Red" and "Princess Blue", special summon one "Royal Princess Purple" from your deck or hand. If you offer "Princess Blue" and "Princess Yellow", special summon one "Royal Princess Green" from your deck or hand. If you offered "Princess Red" and "Princess Yellow", then special summon one "Royal Princess Orange" from your deck or hand. Then shuffle your deck.

Royal Princess Purple ****
Type/Warrior ATT/Light
ATK:1000 DEF:1000
Effect: This card cannot be summoned except by the effect of "Royal Contrast". If your opponent attacks a card with princess in it's card name, then decrease the attack of the attacking monster by 1000 points.

Royal Princess Orange ****
Type/Warrior ATT/Light
ATK:1000 DEF:1000
Effect: This card cannot be summoned except by the effect of "Royal Contrast". If your opponent attacks a card with princess in it's card name, increase the attack of the targetted monster by 500 points.

Royal Princess Green ****
Type/Warrior ATT/Light
ATK:1000 DEF:1000
Effect: This card cannot be summoned except by the effect of "Royal Contrast". Increase the attack of all cards with princess in it's name by 500 points. If a card with princess in it's name is the target of spell, trap, or monster effect, pay 500 LP to negate the effect. This effect can only be used once a turn.

Omega Princess White ************
Type/Warrior ATT/Light
ATK:3000 DEF:3000
Fusion: Royal Princess Purple + Royal Princess Orange + Royal Princess Green
Effect: This card cannot be summoned except by fusion summon, and only with the above fusion material monsters. Increase the attack of all cards with princess in their name by 1000 when they attack or are being attacked. Negate the effect of a card targetting a card with princess in it's card name by paying 500 lifepoints.

Diamond Tiara
Spell-Equip
Effect: You can only equip this to "Royal Princess Purple", "Royal Princess Orange", or "Royal Princess Green". When a card with princess in t's card name attacks, increase it's attack by 500 points.

Princess Armor
Spell-Equip
Effect:You can only equip this to "Royal Princess Purple", "Royal Princess Orange", or "Royal Princess Green". When the equipped monster attacks, increase it's attack by 500 points.

Royal Kingdom
Spell-Continuous
Effect: Whenever a card with princess in it's card name is summoned, special summon one "Royal Guard Token". As long as this card remains face-up on the field, your oponent cannot attack any cards with princess in it's name as long as there is a "Royal Guard Token" on your side of the field.

ANd here is a blue-eyes themed one I just made-up because of my bordom

Blue-Eyes Fighter Jet ********
Type/Machine ATT/Light
ATK:0 DEF:0
Fusion/Union: BLue-Eyes White Dragon + One machine type monster
Effect: This card can only be fusion summoned and only with the above fusion material monsters. This card can be equipped to a warrior type monster with less then 500 attack points. Increase the attack of the equipped monster by 3000 points, and when the monster attacks a defense monster and has higher attack points then the monsters defense, inflict the difference as batle damage. When the monster equipped with this card would be destroyed as a result of battle, destroy this card instead (you still recieve battle damage). When this card is sent to the graveyard, your opponent's turn automatically ends.

Color blind from all of those princesses, lol. Nice set. I like Blue-Eyes Fighter Jet the most just because machine-types are my fave. ^^

I was thinking of making a blue-ees ultimate fighter jet, but I wouldn't know any good effects.

Would be kind of pointless, though, no offense. A Blue-Eyes Ultimate Fighter Jet wouldn't look right to me. XD

Besides, this fighter jet seems powerful enough. =o

I meant to say that too, but I am not sure, do you think it is over-powered?

Well the difficulty it takes to summon it equals the power of the effects, in my opinion, so no.

Thanks, but how is it hard to get out?

I never said it was hard to bring out. All that I was saying was that the tasks required to summon it balance out its power, if that makes sense. ^^:

Now I see what you are saying