Be tickled pink
Definition 1 of 1
Pro Tip 1/3Emotionally Colorful
Indicates strong happiness with a hint of surprise or unexpected pleasure. 
Grandma was tickled pink when we surprised her on her birthday.
Pro Tip 2/3Casual Expression
Best used in informal conversations and personal messages, not formal contexts. 
I'm tickled pink that you could come to my party!
Pro Tip 3/3Positive News
Often used to react to good news or events that bring joy. 
They were tickled pink about the announcement of their daughter's engagement.