To see the original swatches of the Summer Brights collection check out this post.
Sweet Addiction vs. Central Park (New York Style Collection)
|L-R: Sweet Addition, Central Park, Sweet Addiction, Central Park|
The similarities: Both are dusty, creme greens with a touch of blue, they were both easy to apply and very pigmented
The differences: Central Park is darker
Lemon Drops vs. Banana Drop vs. Sunshine
|L-R: Sunshine, Banana Drop, Lemon Drops|
The differences: Sunshine is a cool-toned bright yellow with shimmer, Banana Drops is a pastel creme, and Lemon Drops is a bright yelllow with a touch of warmth. Lemon Drops is the friendliest to apply (although, none of these are exceedingly difficult).
Pink Flip-Flops vs. Allie's Lace Cover Up vs. Pink Quartz
|L-R: Pink Quartz, Allie's Lace Cover Up, Pink Flip-Flops|
The differences: Pink Quartz has a touch of orange, Allie's Lace Cover Up leans lavender, and Pink Flip-Flops has a distinct brightness reminiscent of Barbie. Allie's Lace Cover Up and Pink Flip-Flops are definitely more cool-toned than Pink Quartz. Choosing between these is a matter of preference and skin-tone.
Cosmic Kiss vs. Eli's Magic vs. Life of the Party
|L-R: Life of the Party, Eli's Magic, Cosmic Kiss|
The differences: Eli's Magic is what I would call a true bright pink. It's probably the color most think of when they think of a neutral hot pink. Life of the Party is still very vibrant but it has more coral (warm) undertones. Cosmic Kiss is the coolest of the three.
The only comparison that is not exclusively Barielle, Blue Capri vs. essie Butler Please
The differences: Blue Capri is dustier and a touch darker than Butler Please. Blue Capri is a touch thicker and more pigmented, making application faster and easier.
There are no duplicate polishes here! However, it is not completely necessary to own ALL of these. It's a matter of deciding which ones fit your skin-tone best. Everyone has their own preferences so pick whichever one works best for you. Some do have better formulation than others making for easier application. If I HAD to pick I would choose: Central Park, Banana Drop (but maybe Lemon Drop), Allie's Lace Cover Up, Life of the Party, and Blue Capri.