You are the sunshine of my...

...life, literally. Not only mine but all life, no wonder it was worshipped as a deity in ancient times. 
The visible 'surface' that we see is called the photosphere. It has a temperature of around 5,700°c. Sunspots appear dark by contrast as they are cooler, around 3000-4000°c, still hot mind.
The Sun emits light at all wavelengths so appears white, any yellow or red colouration is a result of the light passing through our atmosphere. 
Do not look directly at the Sun, especially so with optical aid. Proper filtration must be used.