It appears Coca Cola fans are quite an OCD bunch. Used to getting their sweet fix in bottles with colour-coded tops, many like being able to tell whether they're reaching for the 'full fat' regular variety by the red lid on top. But since March the soft drink company has been putting scarlet tops on Diet Coke as well - causing consternation for fans of the zero calorie, zero sugar version. Scroll down for video . Diet Coke bottles like this one now have red lids just like regular Coke - causing a headache for some fans . Coke has switched all the lids on its 500ml bottles to red to 'help make our consumers aware of the full choice available to them within the Coca-Cola range' Fans have taken to Twitter to express their discontent at the changes, which have left many a bit confused . Coke Zero, which is also sugar-free, and the reduced sugar Coke Life varieties also used to have tops with a specific colour, in line with the designs of the labels around the middle. But since March Coca-Cola has made the lids on all of them red, with the aim of bringing all four variants 'together under one brand'. Many drinkers have been left baffled when confronted with the red tops associated with regular Coke on lower calorie and reduced or zero sugar bottles. Charlie Faloona posted on Twitter:  'Why on earth do the new diet coke bottles now have red lids but still a silver wrapper? It doesn't look right'. Helen Smith added: 'Not impressed with the red lids on the diet coke'. Catherine Lightfoot posted: 'Is there a reason why diet coke now have red lids?! Utterly confusing!' Coke Life bottles also have scarlet tops after Coca-Cola decided last month to bring all four variants 'together under one brand' Coca-Cola says the new bottles 'feature a larger label with the distinctive colour and description of the variant clearly displayed' And James Robinson said: 'Coke are messing with our heads. Coke zero used to have black lids. Fat Coke red. Diet coke white. Coke life green'. A Coca-Cola Great Britain spokesperson said: 'We have recently announced we are bringing the four Coca-Cola variants together under one brand to help make our consumers aware of the full choice available to them within the Coca-Cola range. 'As part of this we have introduced a new look across all our Coca-Cola packaging to give a more consistent look and feel. 'The new 500ml bottles now feature a larger label with the distinctive colour and description of the variant clearly displayed and the new red caps have the Coca-Cola variant clearly labelled on the top. 'We have been encouraged by the reaction we've had to the changes so far.' 'The new red caps have the Coca-Cola variant clearly labelled on the top,' say the soft drinks company . Despite the worries expressed by fans, Coca-Cola has said it is 'encouraged by the reaction we've had to the changes so far'
Customers used to white lids on the famous zero calorie, zero sugar type .
Other variants Coke Zero and Coke Life used to have black and green tops .
But company has now brought all four variants 'together under one brand'
Company accused of 'messing with our heads' with red tops for all types .