The Conservatives have denied turning their green "tree" logo blue to appease their traditional supporters.
The Tories say their green logo comes in other colours
The tree was introduced last year by leader David Cameron in effort to give the party a more eco-friendly image.
William Hague's use of a blue "sky" backdrop at an event on Tuesday sparked speculation it had been scrapped.
But a Tory spokesman insisted the tree - described as "a bunch of broccoli" by former party chairman Lord Tebbit - was here to stay.
The Conservatives paid designers £40,000 to replace their traditional blue "torch" emblem with an image representing "strength, endurance, renewal and growth".
The Tory 'tree' logo was introduced last year
Several long-term Tory supporters criticised the design, with Sir Bernard Ingham, press secretary to former prime minister Margaret Thatcher, calling it "barmy".
But a Conservative Party spokeswoman denied Mr Hague's appearance in front of a "clouds and sky"-coloured tree represented a return to traditional, true-blue symbols.
She told the BBC: "We are not changing it at all. When we launched the tree last year there were various colours on it.
"You can change the backdrop on it. You can change the colour of the tree to make it look like a winter tree and things like that."
It is up to organisers of press conferences and other events to decide the backdrop to use, the spokeswoman added.