A richer tone (rather than a pastel) would probably be your best bet then, to flatter everyone. But hey, it's your day so if you love lighter shades that's cool too! They are all going to look great because they are happy to be there for you!
And if you want all the exact same dress, the one thing I'll say is that totally strapless is probably the most controversial. Maybe all your ladies will be happy with it, but often times anyone with a bigger top ends up worried about strapless dresses needing to be tugged up constantly or jeez, even falling down!
Well a "good style" is highly dependent on the wearer so you won't be able to find the right style until you have the gang go to the store and try on dresses. Likewise, reputable styles can also look terrible on certain people.
I think a lot of it depends on your bridesmaids - do they have a mix of complexions and hair colours? Body types? Different comfort levels?
I like different dresses in the same colour, so that each lady can chose whatever style (all from the same place so they go together, but that's me! True mix-and-match can be cute too!) they feel comfortable in.
As for colours, pastels can be tricky to pull off if you have any really pale bridesmaids. And redheads might fight you on pinks (they don't actually look bad in pink/red but from my experience they've been told they do). But jewel tones look good on everybody!
All that said, I think the off the shoulder/Bardot neckline ones in purple that you posted are very chic!
I would choose whatever colors you want to have in your wedding! You only get married once!
As for which style, I like letting everyone choose their own style and what fits them the best and how comfortable they'll be for they whole day.
You’re getting married in the summer, so I would stay away from burgundy as that’s usually a fall colour in my opinion. I like the dusty rose.
I'm like Genevieve and gonna be biased lol one of our colours is purple but more of a light lavender shade since ours will be in spring. What time of year are you getting married? Have you chosen colours/themes yet? As for style, I like letting everyone choose their own style so that I know they'll be at their most comfortable and therefore able to better focus on having a good time while also being able to do their duties with confidence, and just to let their separate personalities shine through too.