Speaker Nancy Pelosi Nancy PelosiPelosi: Trump Supreme Court pick 'threatens' Affordable Care Act Sunday shows preview: Lawmakers prepare for SCOTUS confirmation hearings before election Will Democrats attempt to pack the Supreme Court again? MORE (D-Calif.) and a group of female Democratic lawmakers on Wednesday wore dark clothing on Capitol Hill to mark the House's vote on articles of impeachment against President Trump Donald John TrumpBiden says voters should choose who nominates Supreme Court justice Trump, Biden will not shake hands at first debate due to COVID-19 Pelosi: Trump Supreme Court pick 'threatens' Affordable Care Act MORE.

Rep. Debbie Dingell Deborah (Debbie) Ann DingellOn The Money: Anxious Democrats push for vote on COVID-19 aid | Pelosi, Mnuchin ready to restart talks | Weekly jobless claims increase | Senate treads close to shutdown deadline Anxious Democrats amp up pressure for vote on COVID-19 aid Races heat up for House leadership posts MORE (D-Mich.), who was wearing a dark grey coat with black lapels, told The Hill that some female members of Congress typically wear red on Wednesdays to show solidarity with issues such as human trafficking and women's heart health awareness.

But they decided to wear darker colors this week to mark the "somber" occasion, she said.

ADVERTISEMENT

"Normally we wear red [on Wednesdays] and we said, 'We can't do that today.' So, many of the women are in darker colors because it is a somber day," Dingell added as she left the House floor.

Pelosi, Rep. Val Demings Valdez (Val) Venita DemingsFlorida Democrat introduces bill to recognize Puerto Rico statehood referendum Sunday shows - Trump team defends coronavirus response Demings slams GOP coronavirus relief bill: Americans 'deserve more than the crumbs from the table' MORE (D-Fla.), a member of the House Intelligence Committee, and Rep. Kendra Horn Kendra Suzanne HornKate Schroder in Ohio among Democratic challengers squelching GOP hopes for the House GOP women's group rolls out six-figure campaign for Ernst Trump asked Chamber of Commerce to reconsider Democratic endorsements: report MORE (D-Okla.), who represents a swing district, were among the lawmakers spotted on the Capitol wearing black.

The Speaker told NBC News that she was "sad" about the day's proceedings.

The move to sport dark clothing did not appear to be widely coordinated, however. Female Democratic lawmakers arrived in the House chamber wearing a variety of colors.

Republican Rep. Debbie Lesko (Ariz.) also gave a forceful speech condemning impeachment while wearing a black coat.

ADVERTISEMENT

The Democratic-controlled House is prepared to vote on two articles of impeachment charging the president with abuse of power and obstruction of Congress. Nearly every House Democrat is expected to vote in favor of the articles, which would make Trump just the third president in U.S. history to be impeached.

Ahead of the vote, Pelosi told her Democratic colleagues that they would be "derelict" in their duty if they did not vote to impeach Trump. The impeachment vote follows a House inquiry largely based on allegations that Trump pressured the Ukrainian president to announce investigations into his political rivals.

Trump has repeatedly dismissed charges of wrongdoing.

In a scathing letter sent to Pelosi on Tuesday, the president accused Democrats of waging "nothing more than an illegal, partisan attempted coup."

Cristina Marcos contributed to this report.