The most beautiful colour I ever saw in my life was...

[MorrisZapp]

A periwinkle blue, worn by Cinderella in the Ladybird book of my childhood.

I've never forgotten it, it's somewhere in my DNA now I think.

Love the kerplunk marble! We used to call opaque marbles 'chinas', they were prized.

I love the green of a-road signs.

the pink sky we saw on the way to hospital on the morning of my ERPC with the baby I miscarried.
We named her Yasmin and I told DH that I felt as if she was saying hello to us.

I told that story to the kids a few times and since then whenever there's a pink sky they still comment that it's Yasmin saying hello.

I saw the thread title and came on to say the blue dress in Cinderella OP! I also loved the Crayola Crayon called Periwinkle.

The early morning sky behind naughty pony (he broke his automatic drinker and flooded his stable)

The colour of the sunsets we watched on holiday in Bali a few years ago.

Oooh your title just drew me in; I love colour, it mesmerised me. The best colour I've seen in that mauve lilac of the setting sun on a summers day. I'd follow it until it evaporated, just soaking it in. Alternatively, the inky blue of an autmunal/ winters eve - it's dangerously inticing. I don't think Dulux have bottled it yet and I'm glad.

*mesmerises

The best blue from my childood was from the Flower Fairies - scylla.

I was going to say the blue of the sky when it met the sea and the two were indistinguishable when we came to the brow of a massive hill, between the peaks of two others ahead in the distance with a valley between us and the view, when we got lost off road on a Greek island. It was incredible. This was long before DS, when we could do silly things in off road vehicles.
Having read the other answers I think it's interesting that so many people refer to a shade of blue as the most memorable/evocative. I wonder if there's something to that

Scylla Flower Fairy

The blue colour of lapis lazuli - love it , I have polished and unpolished and prefer the natural rock when the colour seems more intense.

This

@MichelleScarn

This one *@MorrisZapp*

Oh my heart, I remember this book so well. You've made my evening!

The blue of some (probably hideous) plastic jewellery I won in an arcade in Wales on holiday as a child. I loved it so much it makes me feel funny inside when I think about it but I don't remember the jewellery clearly, just the colour.

The colour of DD’s bedroom- a blue called Barking Creek by Valspar in her cosy south facing room.

Makes me think of toddler kisses and the smell of fabric softener from her sheets 🥺

Really interesting so many of us are drawn to blues - most on the thread I think! Off to go down a rabbit hole of psychology and colour now...

@MichelleScarn

This one *@MorrisZapp*

OMG what a flashback!! I totally remember this and thinking it was almost 3D it was so vibrant 💙💙

Metallic magenta, my first bike was spray painted this colour.

Stepping off a fishing boat onto a deserted island off Malaysia. In my mind I had always believed that ‘tropical beach’ postcards were enhanced or filtered but the dark blue sky, turquoise sea and white sand was just totally dazzling.

A boy peacock trying to impress the girls-the brightest cerulean blue, teal, copper and cream. Stunning!

Scarby9 Oh I LOVED the Flower Fairies as a child... always imagined myself as the Speedwell Fairy and I still love that shade of blue.

Turquoise.

@Scarby9

The best blue from my childood was from the Flower Fairies - scylla.

I was obsessed with Flower Faries as a kid. I have a huge book of the poems for each flower. I had wall hangings, greeting cards ornaments. All sorts

I agree about the Disney Cinderella dress! I'm 53 now and it still makes me happy to see it!

I also love turquoise .....makes me think of the beach, summer and holidays. uplifting

i have no blue or turquoise at all in my home decor, strangely