A way to show arbitrary RGB colors on Shuffleboard. Intended for use with the REV Color Sensor.

ShuffleboardRGB.java

import edu.wpi.first.wpilibj.shuffleboard.BuiltInWidgets;
import edu.wpi.first.wpilibj.shuffleboard.ShuffleboardContainer;
import edu.wpi.first.wpilibj.shuffleboard.SuppliedValueWidget;
import edu.wpi.first.wpilibj.util.Color;
import java.util.Map;

public class ShuffleboardRGB {
    public final SuppliedValueWidget<Boolean> widget;

    private static final String offStr = "Color when false";
    private static final String onStr = "Color when true";
    private static final String hexStringFmt = "#%02X%02X%02X";

    public static final String toHexString(Color c) {
        // Float to 0-255 conversion implementation from java.awt.Color
        return String.format(hexStringFmt, (int) (c.red * 255 + 0.5), (int) (c.green * 255 + 0.5),
                (int) (c.blue * 255 + 0.5));
    }

    public ShuffleboardRGB(ShuffleboardContainer tab, String name) {
        widget = tab.addBoolean(name, () -> false).withWidget(BuiltInWidgets.kBooleanBox);
        setColor("#000000");
    }

    public final void setColor(Color color) {
        setColor(toHexString(color));
    }

    public final void setColor(String color) {
        // Hex color string #RRGGBB
        widget.withProperties(Map.of(offStr, color, onStr, color));
    }
}