No, there isn't.

Yes, there is. But it is only understandable for advanced design students.

Yes, it is called 'Colour wheel'.

No, you need to have many colour palettes to understand it.

Sir Isaac Newton

Charles Dickens

Voltaire

Leonardo da Vinci

False

True

True

False

Violet/Red

Blue/Yellow

Green/Blue-Green

Orange-Yellow/Green

Dark yellow-green jeans and yellow blouse

Light blue jeans and red blouse

Violet-red jeans and dark orange blouse

Dark green jeans and light red blouse

Yellow and orange

Red-orange and red

Blue-green and violet

Violet and yellow

False, it is highly recomended to use bright colours, only for specific data you need to highlight.

True, the brighter, the easier to comprehend the information.

False, dark colours require white letters, which is more difficult to read. You can use it, with moderation.

True, you can have your entire spreadsheet in black, like in 'night mode', if you want to.

You must consider your personality, if you are very sweet, you can use pastels and mostly a pink based palette. Use a different tone of pink for each grade.

You must consider colours which already have a special meaning. For example red or yellow. These colours, most of the time indicate a warning, or a risk. If you use it for the grades, the parents may think there is a problem.

You have to consider white and gray as your basic colours. Remember a spreadsheet is not designed for presenting information, like a slide presentation.

You can add charts to your spreadsheet, to make easier to others to understand the data processed, but leave your data and information as neat as possible.

Your borders can have different colours, and they don't have to combine with the colours used.