Contrasting grabs the eyeball and lands it on what is significant, this method is usually done with sizes and colors.
Repetition unifies the whole artwork in order to brace the message the specific design is carrying.
For example using different shades and tones of red simplifies the message and grips the rhythm of a viewer.
A polished visual is known as the aligned one, it provides structure and balance to your creatives, not well-aligned artwork with elements turns out to be boring and sloppy.
If there are short lines and headings then the most used and easy-to-read is the centred alignment to attain a formal look in your work.
Blue is the colour that throws the message of trust and most of the institutes make it their brand colour.
Moods and Reactions rely on colours, and it does have a literal meaning, so the application of warm and cool colours should be carefully considered because each colour in the wheel contains a meaning.
Using not relatable colours to your brand just for the exciting feels, might turn off the viewers also and not give the desired essence of visual creativity, Pre-determined colour palette is not workable.
Yes, you can play and experiments with your own created palettes that could be monochromatic, triad, and complementary if you start off to bring out better results.