You are at : Site Map > Education and Guidance > Understanding Diamonds > Diamond Colour Diamond Colour A poor colour can affect the brightness and brilliance of a diamond.  Colour is graded using an alphabetic scale running from D to Z. It is widely accepted that a colourless diamond is best. The scale starts at D because it is believed that diamonds of A,B and C quality may still be found. The diamond colour scale below illustrates the colour of a diamond and the corresponding code. Diamond Colour Scale Diamond Colour Grading Table The following grading table gives the official grade, colour and accurate comments of the various diamond colour grades. Grade Colour Comments D Absolutely colourless Extremely rare E Colourless Traces of colour. A rare diamond F Colourless Colour is detectable with close inspection. A high quality diamond G / H Near Colourless Colour is noticeable when compared to other diamonds I / J Near Colourless Colour is detectable (slightly) using naked eye K to Z Noticeable colour   Ralph Blacklock only offers for sale diamonds with a colour grade of 'D' or 'G ', click here to read more about our diamond quality. [ Diamond Colour ] [ Diamond Clarity ] [ Diamond Cut ] [ Diamond Carat Weight ] [ Diamond Certification ] [ Diamond Shape ] [ Diamond Care ] [ Diamond FAQ ]