Shades of opinion

I heard some many different versions of what comes after "Roses are red. Violets are blue..."What is the original one and who wrote it? Thanks.

violetsareblue.info/
There can't be anyone who isn't familiar with the original and old favourite to many a Valentine's Day Message!

Roses are red,
Violets are blue,
Sugar is sweet,
And so are you


Violets are purple.

Violet surely?

There will always be different shades of opinion!