One reason is that computer displays are just not very good at reproducing colorful light reds, a limitation of the 3-primary emissive display technology. As a

One reason is that computer displays are just not very good at reproducing colorful light reds, a limitation of the 3-primary emissive display technology. As a result light reds on typical computer displays are always pale/faded looking. This can make it hard to build a useful range of UI colors of red hue, depending on the needs of the UI.