In Delphi VCL, TColor is used to specify the color of a control. It only works for development on Windows.
TColor is used to specify the color of a Windows-only control. It is used by the Color property of many components and by many other properties that specify color values.
The Graphics unit contains definitions of useful constants for TColor. These constants map either directly to the closest matching color in the system palette (for example, clBlue maps to blue) or to the corresponding system screen element color defined in the Color section of the Windows Control panel (for example, clBtnFace maps to the system color for button faces).
If you specify TColor as a specific 4-byte hexadecimal number instead of using the constants defined in the Graphics unit, the low three bytes represent RGB color intensities for blue, green, and red, respectively. The value $00FF0000 (Delphi) or 0x00FF0000 (C++) represents full-intensity, pure blue, $0000FF00 (Delphi) or 0x0000FF00 (C++) is pure green, and $000000FF (Delphi) or 0x000000FF (C++) is pure red. $00000000 (Delphi) or 0x00000000 (C++) is black and $00FFFFFF (Delphi) or 0x00FFFFFF (C++) is white.
If the highest-order byte is zero, the color obtained is the closest matching color in the system palette. If the highest-order byte is one ($01 or 0x01), the color obtained is the closest matching color in the currently realized palette. If the highest-order byte is two ($02 or 0x02), the value is matched with the nearest color in the logical palette of the current device context.
The following table lists the color constants from the Graphics unit. The first two columns list the colors that map to the closest matching color in the system palette, while the last two columns list the colors that are defined in the Windows Control panel:
| Value | Meaning | Value | Meaning |
| clNone | White on Windows 9x, Black on NT. | clScrollBar | Current color for the scroll bar track. |
| clAqua | Aqua | clBackground | Current background color of the Windows desktop. |
| clBlack | Black | clActiveCaption | Current color of the title bar of the active window. |
| clBlue | Blue | clInactiveCaption | Current color of the title bar of inactive windows. |
| clCream | Cream | clMenu | Current background color of menus. |
| clDkGray | Dark Gray | clWindow | Current background color of windows. |
| clFuchsia | Fuchsia | clWindowFrame | Current color of window frames. |
| clGray | Gray | clMenuText | Current color of text on menus. |
| clGreen | Green | clWindowText | Current color of text in windows. |
| clLime | Lime green | clCaptionText | Current color of the text on the title bar of the active window. |
| clLtGray | Light Gray | clActiveBorder | Current border color of the active window. |
| clMaroon | Maroon | clInactiveBorder | Current border color of inactive windows. |
| clMedGray | Medium Gray | clAppWorkSpace | Current color of the application workspace. |
| clMoneyGreen | Mint green | clHighlight | Current background color of selected text. |
| clNavy | Navy blue | clHighlightText | Current color of selected text. |
| clOlive | Olive green | clBtnFace | Current color of a button face. |
| clPurple | Purple | clBtnShadow | Current color of a shadow cast by a button. |
| clRed | Red | clGrayText | Current color of text that is dimmed. |
| clSilver | Silver | clBtnText | Current color of text on a button. |
| clSkyBlue | Sky blue | clInactiveCaptionText | Current color of the text on the title bar of an inactive window. |
| clTeal | Teal | clBtnHighlight | Current color of the highlighting on a button. |
| clWhite | White | cl3DDkShadow | Windows 95 or NT 4.0 only: Dark shadow for three-dimensional display elements. |
| clYellow | Yellow | cl3DLight | Windows 95 or NT 4.0 only: Light color for three-dimensional display elements (for edges facing the light source). |
| clInfoText | Windows 95 or NT 4.0 only: Text color for tooltip controls. | ||
| clInfoBk | Windows 95 or NT 4.0 only: Background color for tooltip controls. | ||
| clGradientActiveCaption | Windows 98 or Windows 2000: Right side color in the color gradient of an active window’s title bar. clActiveCaption specifies the left side color. | ||
| clGradientInactiveCaption | Windows 98 or Windows 2000: Right side color in the color gradient of an inactive window’s title bar. clInactiveCaption specifies the left side color. | ||
| clDefault | The default color for the control to which the color is assigned. |
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