iOfficeAI/OfficeCLI · error · ArgumentException

Invalid threshold '{parts[i]}' in colorRule.

Error message

Invalid threshold '{parts[i]}' in colorRule.

What it means

In the multi-zone colorRule form (t1:c1:t2:c2:...:cN), every odd-indexed segment (parts[0], parts[2], ...) must be a numeric threshold. The parser iterates in steps of 2 and checks each threshold. If any threshold fails double.TryParse, the library rejects it with 'Invalid threshold'. This is the multi-zone path (parts.Length != 3); the simple path has its own error (error 128).

Source

Thrown at src/officecli/Core/Chart/ChartHelper.Advanced.cs:322

        string topColor;

        if (parts.Length == 3)
        {
            // Simple two-zone: threshold:belowColor:aboveColor
            if (!double.TryParse(parts[0], System.Globalization.NumberStyles.Float,
                System.Globalization.CultureInfo.InvariantCulture, out var t))
                throw new ArgumentException($"Invalid threshold '{parts[0]}' in colorRule. Expected a number.");
            rules.Add((t, parts[1].Trim()));
            topColor = parts[2].Trim();
        }
        else
        {
            // Multi-zone: t1:c1:t2:c2:...:cN
            for (int i = 0; i < parts.Length - 1; i += 2)
            {
                if (!double.TryParse(parts[i], System.Globalization.NumberStyles.Float,
                    System.Globalization.CultureInfo.InvariantCulture, out var t))
                    throw new ArgumentException($"Invalid threshold '{parts[i]}' in colorRule.");
                rules.Add((t, parts[i + 1].Trim()));
            }
            topColor = parts.Length % 2 == 1 ? parts[^1].Trim() : rules[^1].color;
            if (parts.Length % 2 == 0)
                rules.RemoveAt(rules.Count - 1); // Last pair has no "above" — use as topColor
        }

        // Apply to each data point in each series
        foreach (var ser in plotArea.Descendants<OpenXmlCompositeElement>().Where(e => e.LocalName == "ser"))
        {
            var values = ReadNumericData(ser.GetFirstChild<C.Values>())
                ?? ReadNumericData(ser.Elements<OpenXmlCompositeElement>().FirstOrDefault(e => e.LocalName == "yVal"));
            if (values == null) continue;

            for (int pi = 0; pi < values.Length; pi++)
            {
                var val = values[pi];
                string pointColor = topColor;

View on GitHub (pinned to 1ced45e900)

Solutions

  1. Ensure every odd-positioned segment (0-indexed: 0, 2, 4, ...) is a numeric threshold: '0:FF0000:50:FFAA00:100:00AA00'.
  2. Verify the segment count matches the intended threshold:color pairs plus an optional trailing top color.
  3. Check for accidental extra colons that misalign the threshold/color pattern.

Example fix

// before
colorrule: "0:FF0000:abc:00AA00:100:FFFF00"
// after
colorrule: "0:FF0000:50:00AA00:100:FFFF00"
Defensive patterns

Strategy: validation

Validate before calling

static bool AreMultiZoneThresholdsNumeric(string spec)
{
    var parts = spec.Split(':');
    if (parts.Length <= 3) return true; // not multi-zone
    for (int i = 0; i < parts.Length - 1; i += 2)
    {
        if (!double.TryParse(parts[i], System.Globalization.NumberStyles.Float,
            System.Globalization.CultureInfo.InvariantCulture, out _))
            return false;
    }
    return true;
}

Try / catch

try { ChartHelperAdvanced.ApplyColorRule(plotArea, spec); }
catch (ArgumentException ex) when (ex.Message.Contains("Invalid threshold") && !ex.Message.Contains("Expected a number"))
{
    Console.Error.WriteLine($"A threshold in multi-zone colorRule is non-numeric.");
}

Prevention

When it happens

Trigger: Passing a multi-zone colorRule where any threshold segment is non-numeric: '0:FF0000:abc:00AA00' or 'x:FF0000:50:00AA00:100:FFFF00'. The spec must have more than 3 colon-separated parts.

Common situations: Mismatching the alternating threshold:color pattern — placing a color where a threshold belongs. Using locale-specific decimal separators. Adding an extra colon that shifts the even/odd alignment of segments.

Related errors

AI-assisted analysis of iOfficeAI/OfficeCLI@1ced45e900 (2026-08-13). Data as JSON: /api/errors/ad1ffc1b0467315b. Report an issue: GitHub.