lighten up

verbs

make more cheerful
"the conversation lightened me up a bit"
buoy up, lighten, lighten up
become more cheerful
"after a glass of wine, he lightened up a bit"
buoy up, lighten, lighten up
make lighter or brighter
"The paint will brighten the room"
brighten, lighten, lighten up
become lighter
"The room lightened up"
lighten, lighten up