## Why

The current candlestick chart uses green and red colors which may not provide optimal visual contrast or match the desired aesthetic. Updating to a classic black/white color scheme will improve readability and provide a more traditional financial chart appearance.

## What Changes

- Update up candles (bullish) to display with white interior and black outline
- Update down candles (bearish) to display as completely black
- Modify wick colors to match the new color scheme

## Capabilities

### New Capabilities
<!-- No new capabilities being introduced -->

### Modified Capabilities
- `chart-canvas`: Updating the candlestick series color configuration to use black/white scheme instead of green/red

## Impact

- Affects `src/components/CandleChart.tsx` where candlestick series colors are configured
- Visual change only - no API or data structure changes
- No breaking changes to functionality
