Chinese adore the colour red. It a very Yang colour in terms of Feng Shui. Indeed, it is so auspicious that most of the Forbidden City is painted in red!
Red is a very vibrant colour, it is very stimulating visually and subconciously.
Red is a very dominant colour and is best used in moderation; Feng Shui always emphasizes on balance & moderation. Red decors are best placed in the south, northeast & southwest sections of one environment ( according to the 8 mansion school ).
However, one needs to be careful not to use the colour red when a particular section is afflicted by bad annual stars, namely the 5 yellow & 2 black ( flying star feng Shui )
I personally like to use red in the living room or kitchen/dining room as these are the areas for socializing and would much benefit from a dose of Yang Chi boosting.
I prefer to use red decor moderately in my personal space, as a scarlet furniture/ornament will automatically be the centre of attention / attraction. Abundant yang energy is great for public area but one could be overstimulated / overwhelmed if this strong colour is saturating ones personal space
In the practice of Feng Shui, red can also be used to energize an object ( cinnabar ink, red knots, red packet, even red stickie ). I activate my Feng Shui objects by sticking red stickies underneath or decorating them with red ribbons.