Colour can convey emotion
Yes, colour can convey emotion in your photos, but how? After seeing a photo, how will you feel? It depends on the psychological impact of the photo. For example, the colour red conveys love, energy, and passion. On the other hand, the colour yellow conveys joy and optimism, and blue conveys calmness and silence. Grey conveys sadness.
Have you ever thought about why you feel melancholic while it is raining or with a cloudy sky? Why do you feel joyful during spring? Yes, it is because of the colour.
Photographers understand the psychological effects of colour and use them to convey the mood or intended message of the photo.