A traditional English song from 1680, very popular even today. Oh yes, a happy happy video. 

See a more traditional version of this song: Lavender's Blue.

Lavender's blue, dilly, dilly
Lavender's green,
When I am king, dilly, dilly
I will be queen.

Who told you so? dilly, dilly, who told you so?
I told myself, dilly, dilly, I told me so.

Who told you so? dilly, dilly, who told you so?
I told myself, dilly, dilly, I told me so.

If your dilly-dilly heart feels the dilly-dilly way
And if you answer 'yes'
In a pretty little church on a dilly-dilly day
I'll (you'll) be wed in a dilly-dilly dress, oh

Lavender blue, dilly, dilly
Lavender green,
Then I'll be king, dilly, dilly
I'll be your queen.
Let love begin, dilly, dilly
I'll (you'll) be your (my) king (queen)

LAVENDER= A plant with purple flowers and an intense nice smell. I'm afraid it's neither green nor blue (see picture)

WHO TOLD YOU SO?= Who told you that?
We can use SO meaning "it" with some verbs:
- I don't think so = I don't think that
- I suppose so = I suppose it
- She doesn't believe so = She doesn't believe it
- I told you so = I told you that

CHURCH= A Christian temple.