MTN yellow, Vodacom red or Orange orange? How about Springbok green?
Whether businesses can use colour to distinguish their brands from their competitors is a question brought into sharp relief by a court case in the US involving Christian Louboutin's distinctive red-soled ladies' shoes.
The US Appeals Court in Manhattan ruled that Christian Louboutin's US trademark registration for its red-soled shoes was valid as these soles had become associated with the designer and so denoted origin.
Kathy Lee, associate in Edward Nathan Sonnenberg's intellectual property department, said that while the use of colour as a trademarkable trait is growing, the burden of proof rests with any firm that wants to trademark a colour.
"European courts say that not only must the colour or other feature that is supposed to be a trademark be capable of distinguishing the product of one company from that of another, but it must be possible to represent that feature in a graphic form.
"The mark that is lodged must also be very clear."
The process for having colours associated with companies registered as part of protected trademarks is onerous, Ms Lee said.
It is complicated further by the heavy burden of proof placed on a company that wants to register a particular colour.
The main reason for this is that the average consumer does not recognise shapes and colours as part of branding. Another reason is that it is hard to trademark colours and shapes, in particular, as designs can be the result of technical solutions.
According to Ms Lee, functional shapes enjoy limited trademark protection under European and South African law.
Shape as a distinguishing feature came under scrutiny in a recent UK case. When Cadbury applied to register the colour purple as a trademark in the UK, the application was very specific - it covered "chocolate in bar and tablet form" and it was for the colour represented by pantone 2685C "applied to the whole visible surface, or being the predominant colour applied to the whole of the visible surface of the packaging".
"The application was accepted because Cadbury was able to show that the colour had been used in relation to the goods on a very large scale, and that it was associated with the product," said Ms Lee.
"But rival Nestlé opposed the application, arguing that the use of the expression 'predominant colour' introduced uncertainty - it was subjective, indeterminate and allowed for alternatives. As a result, the matter ended up in the high court."
In contrast, South African trademark authorities refused a Cadbury application to register its colour purple a few years ago.
Lee said the Cadbury judgment in the UK was unlikely to persuade South Africa's Advertising Standards Authority (ASA) that it should be better disposed towards colour trademarking.
"The ASA has made it clear on more than one occasion that it does not feel that colour can be monopolised.
"A few years ago, it rejected an attempt by iBurst to claim a monopoly on the colour orange, and in a very recent decision it held that Canderel did not have exclusivity to a colour combination of red and yellow in the sphere of sweeteners."
However, this has not stopped other South African companies trying to trademark certain colours as part of their brands.
Lee said cellphone network operator MTN is applying for trademark involving the colour yellow. According to her, the basic test a company must pass to have a colour registered as part of its trademark involves having to prove its distinctiveness through extensive use.
French group Orange Telecommunications is reportedly planning to enter the South African market.
In the UK, the group already holds a trademark over the shade of orange pantone 151 within the telecoms market.
"Colour trademark registrations have not yet gained much traction in South Africa, but they do remain an option for South African companies," Ms Lee said.
"However, courts and trademark authorities would be very wary when it comes to colour marks and the potential for such marks to create perpetual, unjustified monopolies where they shouldn't.
"Any company submitting such an application needs to consider their approach, and reasons for doing so, very carefully before proceeding," Ms Lee said.
* This article was first published in Sunday Times: Business Times