Katharine McPhee Goes Blonde for ‘American Idol’ Finale: Pic

I told you everybody is asking to go #blonde even @katharinemcphee I can't wait to watch she and @jlo perform tonight on @americanidol ????? FORMULA I did a #fullhead of #babylights with @redken5thave #flashlift 40 volume peroxide with 1/4 oz of #olaplex and #balayage ends at the same time ? rinse but #olaplexandwater treatment combed out then rooted with #shadeseq 09nb+09n hairline and roots with 07nb+07n 20 minutes ? rinse ? do a #drop (4oz clear gloss with a drop of 01b #shadeseq and 4 oz of process solution on/off) to get rid of brassy to make it white ?? shampoo #blondeidol and condition with #chemistrysystem #extreme #moisture and #allsoft @mechesalonla @olaplex #redkenready #americanidol #laporsharenae is my choice tonight styled by @chadwoodhair tonight?????

A post shared by Tracey Cunningham (@traceycunningham1) on Apr 7, 2016 at 6:26pm PDT

Going out with a blonde!

American Idol’s series finale on April 7 brought out star-studded alumni decked in their Thursday best. While Carrie Underwood dazzled in two sheer-skirted dresses, season 5 runner-up Katharine McPhee debuted a major hair change, dying her lob from brunette to blonde.

“Blondes have more fun…. At least for 3 months,” McPhee, 32, posted on April 6.

Redken celebrity colorist Tracey Cunningham was the mastermind behind McPhee’s lighter locks. The hair pro, who noted via Instagram that “everybody is asking to go blonde,” gave her client a full head of baby lights.

"Katharine is on hiatus [from her CBS show, Scorpion] for a few months and wanted a change. She’s been the same color for a while," Cunnigham tells Us Weekly. "She loved the end result and will keep it this way until she has to go back to work and return to brunette. With the warmer weather though, it may keep it a little lighter."

To create a natural finish, "we rooted with Redken Shades of EQ Gloss, which gives it more of a grown out look, like she's had this for a long time, Cunnigham tells Us. To help the new color pop, hairstylist Chad Wood crafted the “Over It” songstress’ style into textured waves.

#americanidolseriesfinale ready!! @chadwoodhair

A post shared by Katharine McPhee (@katharinemcphee) on Apr 7, 2016 at 3:31pm PDT

For her last Idol performance, McPhee joined season 9 finalist Casey James for a rendition of Lady Antebellum’s “Need You Now.” Before hitting the stage, she reflected on the show’s lasting impact.

“Today is a special day for a show that not only shaped and influenced pop culture for over the last 15 years but a show that changed so many lives. Mine included,” she captioned an April 7 Instagram post.