The witnesses looked fine. David Holmes and Fiona Hill went to the Longworth Office Building on Thursday morning to testify at the impeachment hearings, and their clothes were reassuringly, dutifully dull. Their dark suits were regulation professional. His tie was subdued, and his hair was perfect. Her necklace was discreet.

To be clear, their attire wasn’t unattractive or ill-fitting. In fact, Holmes’s suit appeared to be tailored from a wonderfully nubby tweed in a subtle, deconstructed plaid of navy and black. Hill’s necklace of metal chain links was artfully raw. But their clothes weren’t flamboyant, boastful or self-conscious. They were shorthand for the professionals who wore them.

These career diplomats, bureaucrats, keepers of obscure but incredibly important knowledge, swore to tell the truth and then sat at the wooden table to face the House Intelligence Committee. They were serious but not grim. They occasionally laughed. In their answers, they tried mightily “to be clear” rather than succinct.

Holmes, a senior staff member at the U.S. Embassy in Ukraine, described overhearing President Trump on a mobile phone conversation with Gordon Sondland, the ambassador to the European Union. Holmes testified that he heard the president loudly ask the ambassador about the Ukrainian “investigations” into the Biden family, which are part of the alleged quid pro quo at the center of the impeachment hearings.

Holmes unspooled his narrative with little fanfare or grandstanding. He was adamant in his certainty. When he took questions from the dais, he did so with his head tilted slightly up and to the right. He patiently swatted away inquiries about issues that preceded his arrival in Ukraine; he would not be rushed despite the ticking timer; he was comfortable wading through the weeds of a Jim Jordan (R-Ohio) soliloquy.

Hill, a Russia expert formerly with the White House, was there to explain the concerns that national security officials had about Trump’s European Union ambassador pushing for the Biden investigations. She emphasized to the committee members and their lawyers that she had come as a fact witness and would not be offering her opinions. But she certainly offered analysis. The British-born Hill, with her clipped accent, delivered a brief opening statement, but when it was time for questions, each of her answers was a mini-TED talk delivered in a that’s-the-end-of-that tone.

Other career officials have testified during these hearings, but Holmes and Hill are especially striking because they arrived perfectly wardrobed in the style of Washington’s anonymous, conscientious power brokers: both the masculine and feminine versions. Their power is in their experience, their institutional knowledge and the quiet counsel they provide to the showmen who actually pull the levers and make the speeches. But when the expertise of the Holmeses and Hills are ignored, that’s all too often when events go sideways.

In general, these creatures of the capital city boast résumés with a long list of degrees that make them experts on countries that most folks only know as answers on “Jeopardy!” Without their slightly peevish emphasis on the correct pronunciation of “Kyiv,” all of us would still be saying it wrong. Theyre often portrayed as awkward or drab, but more often they’ve led colorful, cosmopolitan lives full of harrowing and absurd adventures.

At a distance, and at a glance, people will often misread their clothes as frumpy. Sometimes that’s true, but look closely and you’ll find that the clothes of career diplomats and bureaucrats are often modern and relevant and proper. In the case of Holmes and Hill, their attire reflected the situation. They were dressed to make plain everything that diplomats do. Most definitely, they never distract.

Their wardrobe also underscored the role that these two witnesses play in the drama unfolding on Capitol Hill. Their clothes are “in style,” but they are the sort of clothes one wears to cede the spotlight to others. And there are plenty others willing to take center stage.

On Wednesday, Rep. Devin Nunes (R-Calif.) wore eye-popping pinstripes and checks and polka dots all in one ensemble. Rep. Jim Jordan (R-Ohio), who prefers to drape himself in an roiling cloud of fury instead of a suit jacket, on Thursday wore a bold windowpane check shirt. Rep. Terri A. Sewell (D-Ala.) has hewed to bold primary colors. Rep. Elise Stefanik (R-N.Y.) favors brights hues and the occasional animal print.

There are a lot of people in Washington whose jobs depend on being seen. But it’s the ones who are ferociously, unapologetically dull who are often the most comforting — and, sometimes, the most important.

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