"Hot-hotter-the hottest"
Warmth and coldness are relative concepts. Intuitively, we feel that warmth is fire, while coldness is ice. The same logic can help us orient ourselves in colors. Red towards yellow becomes warmer, red towards blue becomes cooler. The same goes for yellow: closer to red it is warmer, towards blue it is colder.
But with blue there is a trick. Blue leaning towards red is warm, but towards yellow? Isn't something illogical here? Because theoretically, towards yellow, the color should become warmer. But no, blue in the direction of green is considered cold. That's how it is.
Now the question is, what should we do with this information?
For example, take a look at the picture of an object that is half in shadow and half in the sun. What shade does each side take on?
Summary
Shades of the same color can be warm or cool.