This is a simple script that colors bars/candles based on where price is relative to the basis, and the upper and lower bands of the Bollinger Bands.
If price is above the basis, candles will be colored green, and if price is below the basis, candles will be colored red.
If price is outside of the bands on either side, the candles will be colored a darker shade of either color depending on if it is above or below.
I created this indicator because I like that at a glance I can have an idea of the bullishness or bearishness of price action based on the Bollinger Bands, without actually having the Bands overlayed on my charts.
It's also quite nice because I find that the areas where there is a shift in candle color (especially from green to red and vice versa) aid in identifying levels of support and resistance, and shifts in market structure.
I have another indicator that is a huge modification of the Bollinger Bands %B, which includes the candle coloring (and MAs), but this frees up space on my chart while still providing me with the primary information I'm looking for.