The 24-staff UK agency now displays its logo in black (above). The tech firm has more than 135,000 staff, and a logo which appears as white writing on a red background.
Oracle Group's logo was previously red and grey (right).
Oracle Group said a solicitor woking on behalf of Oracle Corporation contacted the agency because of the "potentially confusing" red colour in the PR firm's original logo.
A statement from the agency said it "reluctantly" agreed to change its logo design, despite there being no conflict with the US tech firm.
Oracle Corporation was yet to comment at the time of publication.
An intellectual property lawyer at the firm Bates Wells Braithwaite told PRWeek that these types of disputes tend to result in the larger company getting its way.
He said they could generally be settled either by a deal being struck between the two parties, as was the case in this instance, or after a 'cease and desist' letter is sent, rather than more formal legal proceedings.
The PR agency said that rebranding the business allowed it to highlight the five services it now offers, namely PR, social, marketing, events and digital.
Oracle Group also restructured its management team, including appointing founder Caroline Coskry as chief executive, and promoting Zoe Murzell to MD of PR and events and Jaclyn Thorburn to MD of digital and marketing.
Coskry, who founded the agency in 2011, said: "As we approach our sixth year, it was a good opportunity to refresh the brand and establish our range of capabilities as an expert team of marketers. Whilst we have not changed the logo design, we have opted for a new colour palette, which helps us distinguish our expertise, all under one Oracle Group brand."
Thorburn, who was previously director of strategic comms, added that there had been no redundancies as a result of the restructure.
The agency’s current roster of clients includes property developer Notting Hill Sales and fitness brand Motiv8.
Oracle is not the only business to have refreshed its brand after contact with lawyers this month.
You've got to admire his cheek https://t.co/bVcmSqIenD— Matt Westcott (@mattwecho) June 26, 2017