Please see the tooltip provided by the 'Secondary Symbol' input for more details with regards to properly using this script on symbols that have vastly different valuations, it will help with getting the symbol requested to scale properly with the primary symbol on the chart.
The user may also input which colors are used for / candles as well as the symbol itself and its resolution.
IMPORTANT NOTE: THIS SCRIPT DOES NOT ACCOUNT FOR SYMBOLS THAT ARE NOT CONTINUOUS (The defval for the symbol is TVC:DXY which closes on weekends whereas a cryptocurrency like Bitcoin does not stop trading ever; candles on these kinds of markets will be repeated when overlaid onto markets that do not have this property.)
Change suggested by @AtomOfScent enacted, the addition of bordercolor does help nicely and I had skimmed over it in the reference manual. Ty for the suggestion.
In true TradingView spirit, the author of this script has published it open-source, so traders can understand and verify it. Cheers to the author! You may use it for free, but reuse of this code in a publication is governed by House Rules. You can favorite it to use it on a chart.
Btw, the default plotcandle is broken. If you change line 79 to the following it'll look much better. Bordercolor should equal the candle color unless explicitly changed @PineCoders
plotcandle(o, h, l, c, color = candle, bordercolor = candle)