All colours (apart from the orange spectrum) have a warm and cool undertone version so a colour that we may call “red”, “burgundy” or “maroon” could be either warm or cool.
Red is a colour that has many permutations, from baby pink to coral, magenta and burgundy. Unlike blue or green, that when we add white to (tint) we just call “light blue” or “light green” and when we add black to, we call “dark blue” or “dark green”; red’s shades and tints get their own special names such as pink, not “light red” and “coral” meaning a warm light red.
Distinguishing the Undertone of Red
To tell the difference between a warm undertone red and cool undertone red it’s all about the yellow and blue.
Add a little yellow to your red (more tomato) and it becomes warmer in undertone.
Add a little blue to your red (more raspberry) and it becomes cooler.
How to differentiate a warm burgundy from a cool one?
Burgundy is basically a darker shade of red (a shade is a colour with black added to it).
Just like with the red, adding a little yellow to a shaded red turns it slightly browner and makes it warmer.
Whilst the cool burgundy shades may have either a little more blue (so it’s a dark pink), or just a little more black.
You can see in this image above that the warmer burgundy shades look a little more “burnt”.
While here I’m wearing a very cool burgundy (that looks like a dark pink colour).
More Tips on Distinguishing The Undertone of Colours