The phrase "a welcome bit of" is correct and usable in written English.
It can be used to express appreciation for a small, positive addition or occurrence in a situation.
Example: "After a long day at work, finding a note from my friend was a welcome bit of cheer."
Alternatives: "a pleasant piece of" or "a nice touch of".
A welcome bit of colour in a drab landscape?
The surrender of General Hashem was a welcome bit of good news to the White House.
Serve with poppadoms scrunched over the top for a welcome bit of crunch.
The accents, however, are authentic, a welcome bit of local color in a neutralized television landscape.
Inside, the dash wears an asymmetrical treatment befitting the BMW Z4, a welcome bit of derring-do.
It's one of the only ones with nuts, which provides a welcome bit of crunch in a sea of stodge.
These two photographs, separated by 30 years, illustrate the transition of the Hudson River shoreline from a declining maritime port to a dismal traffic corridor to a blank-faced institutional backwater to a slender — but welcome — bit of parkland.
Next the OFT will publish its study of current accounts, which should lay bare just how "so-called free banking" (a rare and welcome bit of regulatory irony) is propped up by often unclear and unreasonably high costs on everything from using plastic on holiday to not processing transactions quickly enough.
It is an unusual (and welcome) bit of curatorial frankness.
The most welcome bit of budget news for those on low to middle incomes was the decision to change the government's childcare support plans to offer more generous help to families eligible for universal credit in which both parents work.
Hamid Karzai's announcement on Tuesday that he will support a run-off election, after Afghanistan's independent election commission recognised that wide-scale vote-rigging had taken place, is welcome bit of good news amid the regular stream of bad that comes out of Afghanistan.
