There was a photo, old and wrinkled, that Lawrence kept in his wallet at all times. It was of his late wife, a silly grin slapped across her face, proudly holding their son with stained hands.
"You dyed his hair? Why?" He'd asked, shocked.
"Why not?" She giggled happily, and since there was no harm in it, they'd kept it.
When she passed away, Lawrence thought of letting the dye pass as well, but Ferb was adamant on keeping it. Once a month he would re-dye the fading green, and hoped that, somewhere above, his mother gave a silly grin.