iOfficeAI/OfficeCLI · error · ArgumentException

Invalid color value: '{value}'. Expected 6-digit hex RGB (e.

Error message

Invalid color value: '{value}'. Expected 6-digit hex RGB (e.g. FF0000), 8-digit AARRGGBB (e.g. 80FF0000), 3-digit shorthand (e.g. F00) or 4-digit #RGBA shorthand (e.g. F00A), named color (e.g. red), rgb()/rgba()/hsl()/hsla() notation, or 'transparent'.{schemeHint}

What it means

Thrown by ParseHelpers.SanitizeColorForOoxml when, after trying named/rgb/hsl/transparent, #RRGGBBAA, AARRGGBB, 3- and 4- shorthand and 'auto', the remaining hex is not exactly 6 hex digits. The function returns (rgb6, alphaPercent) for srgbClr val. If the input is a recognized scheme color name, the message is extended with a schemeHint telling you to set it on a theme-color-aware property instead.

Source

Thrown at src/officecli/Core/ParseHelpers.cs:772

                hex[0], hex[0], hex[1], hex[1], hex[2], hex[2], hex[3], hex[3],
            });
            var rgb = expanded[..6];
            var alphaByte = Convert.ToByte(expanded.Substring(6, 2), 16);
            if (alphaByte == 0xFF)
                return (rgb, null);
            return (rgb, (int)(alphaByte / 255.0 * 100000));
        }

        if (hex.Length != 6 || !hex.All(char.IsAsciiHexDigit))
        {
            // Scheme colors (accent1, dark2, hyperlink, …) are not handled
            // here — callers that support theme colors must check
            // IsSchemeColorName first and route to ThemeColor. Surface a
            // hint instead of advertising support we don't provide.
            var schemeHint = IsSchemeColorName(trimmedInput)
                ? " (scheme color names like 'accent1' must be set on properties that accept theme colors)"
                : "";
            throw new ArgumentException(
                $"Invalid color value: '{value}'. Expected 6-digit hex RGB (e.g. FF0000), " +
                $"8-digit AARRGGBB (e.g. 80FF0000), 3-digit shorthand (e.g. F00) or 4-digit #RGBA shorthand (e.g. F00A), " +
                $"named color (e.g. red), rgb()/rgba()/hsl()/hsla() notation, or 'transparent'." + schemeHint);
        }

        return (hex, null);
    }

    // ==================== CJK Text Width Estimation ====================

    /// <summary>
    /// Returns true if the character is CJK ideograph, fullwidth, or CJK punctuation.
    /// These characters occupy approximately 1em width (≈ fontSize) vs ~0.55em for Latin.
    /// </summary>
    public static bool IsCjkOrFullWidth(char ch)
    {
        // CJK Unified Ideographs
        if (ch >= 0x4E00 && ch <= 0x9FFF) return true;

View on GitHub (pinned to 1ced45e900)

Solutions

  1. For a literal color use one of: 'FF0000', '#FF0000', '#FF0000AA' (CSS alpha-last with #), '80FF0000' (AARRGGBB without #), 'F00', 'red', 'rgb(255,0,0)', 'transparent', 'auto'.
  2. If the message carries the schemeHint, move that value to a property that accepts theme/scheme colors (the srgbClr path cannot store it).
  3. Mind the # convention: with '#' an 8-hex value is RRGGBBAA (alpha last); without '#' it is AARRGGBB (alpha first).

Example fix

// before
color="accent1"   // on a non-theme-aware property
// after
color="4472C4"     // literal hex, or route accent1 to a theme-color property
Defensive patterns

Strategy: validation

Validate before calling

static bool IsAcceptableOoxmlColor(string value)
{
    try { var _ = OfficeCli.Core.ParseHelpers.SanitizeColorForOoxml(value); return true; }
    catch { return false; }
}

Try / catch

try { var (rgb, alpha) = ParseHelpers.SanitizeColorForOoxml(value); }
catch (ArgumentException ex) { /* surface error, especially the schemeHint if present */ }

Prevention

When it happens

Trigger: Calling any srgbClr-based color setter routed through SanitizeColorForOoxml (Word/PPT fill, line, theme, gradient stops, drawing effects, chart series colors, axis) with a value that isn't 6-hex RGB, 8-hex, 3-/4-shorthand, named, rgb()/hsl(), 'transparent', or 'auto'. A scheme name like 'accent1' triggers the appended schemeHint.

Common situations: Passing a scheme color ('accent1','dk1','hyperlink') to a property that emits srgbClr (no themeColor handling); passing a 5- or 7-digit hex; passing 'rgb(300,0,0)'; misspelled color name; passing an RGBA 8-hex WITHOUT the '#' when you meant CSS RRGGBBAA (bare 8-hex is treated as AARRGGBB).

Related errors

AI-assisted analysis of iOfficeAI/OfficeCLI@1ced45e900 (2026-08-13). Data as JSON: /api/errors/0a2b81e85e23c556. Report an issue: GitHub.