With a big light-dark contrast you make a statement. It usually comes across very hard. This contrast is related to dominance: it dominates the viewer. Secondly, high contrasts in general do have an activating effect, because it attracts the attention immediately.
Example of a dominating palette.
Example of a compliant palette.
A monochrome palette, in which only one colour is varied in brightness and saturation, causes under-stimulation and is significantly combined with desaturated colours and small lightness- and saturation contrasts (Michiels, 2016).