Red is an easy way to get someone's attention. But it's tough to have great contrast against some reds, and lighter reds can easily become pink.
Red does not have much in the lighter range but has more in the darker range, and even then color psychology will tell you whether a color is red, pink, or brown. The light red here could pass as a pink in a vacuum but color psychology is the whole reason it reads as red here.
RGB Red (#FF0000) is very saturated and orange-leaning. Its use is not recommended for bigger areas, and you can see why.
General Rules
- You should never have the red channel at 100%/255 unless you intend to make a lighter red.
- Middle and light reds should ideally have the green and blue channels at non-zero.
- Some neutral reds have blue in them, like with the example background in this webpage. RGB Red leans towards orange.
- If your red is too light it becomes pink. And even the line between red and pink also depends on context.
Examples coming soon!
Maroon
Dark red can be considered to fall into this category. Generally the blue channel will be greater than the green channel. (If the green channl is greater than the blue channel then it could be considered a brown instead.)