This is the 10904th most frequent Swedish word.
ljusa
"Ljusa" means "brighten" or "lighten" in English.
In this sentence, 'ljus' (singular form) describes the dress as having a light tone.
Till festen valde hon en ljus klänning.
For the party, she chose a light-colored dress.
The word 'ljusa' is used as an adjective to describe the evenings as bright.
Jag älskar de ljusa kvällarna på sommaren.
I love the bright evenings in the summer.
Here, 'ljusa' modifies 'färger' (colors), indicating that the colors are bright or light-toned.