How to make an overlay turns from dull to bright

Creator's Corner
1

Can some tell me how to make an text overlay turns from dull to bright?

3

How to make it fade in

4

Work with the opacity

@overlay OLNAME opacity 1 in 1
@overlay OLNAME opacity 0 in 1
@overlay OLNAME opacity 1 in 0
@overlay OLNAME opacity 0.5 in 3

5

Thank you

6