Displays "spike days" by colouring the bars (Default: yellow for a Spike High and blue for a Spike Low)
Spike Day's definition taken from Jack D Schwager's Book: A Complete Guide to the Futures Market: Technical Analysis, Trading Systems, Fundamental Analysis, Options, Spreads, and Trading Principles
A spike is:
A wide difference between the spike high and the highs of the preceding and succeeding days.
A close near the low of the day's range.
A substantial price advance preceding the spike's formation.
The more extreme each of these conditions, the greater the likelihood that a spike high will prove to be an important relative high or even a major top.