See what stars are wearing (or ditching) this week

Rex USA; WireImage; Getty

This week’s hottest trends were all about lightening (and loosening) up for spring.

Up: Cute Jackets. What do you do, clothing-wise, on a spring day that ranges from 30° to 75° within a few hours? If you’re a celeb like, say, Michelle Williams (above left, in Kate Young for Target), January Jones, Nikki Reed or Olivia Palermo, you plan a whole outfit around your favorite blazer or duster. No more hiding them under a coat — now’s the time to show them off!

Down: Perfect updos. Angelina Jolie‘s sedate bun, without a hair out of place, is very pretty (and event-appropriate) but fewer stars are wearing such staid hairstyles on the red carpet these days. You’re much more likely to see loose waves or bedhead-y blowouts.

Up: Yellow dresses. We saw this sweet, sunny hue on stars including Olivia Wilde (above, in Monique Lhuillier), Kate Mara and Olivia Palermo (yes, again). Yellow can be tricky to wear, but we may not be able to resist working it into our wardrobe in small doses.

For more on which trends to follow check out our thoughts on clear clutches and bridesmaid heels.

–Alex Apatoff