A knowledgeable source tells BuzzFeed the answer is in a bit of cosmetic technology used commonly by celebrities: spray tanning.
The Republican nominee has made a habit of spray tanning before major speeches, debates, interviews, and other events that have a chance of getting wide TV coverage, the source said. He pays for the process out of pocket — sparing his campaign the expense, and the task of masking it on public campaign finance reports — and steers clear of public salons where he could be recognized. Instead, he gets misted down in the comfort of his own home or hotel suite.
Via The Political Wire.