How to get the foreground/background color in photoshop.

Question

I want to get the foreground or background color at runtime ( by any action ) in photoshop.
What steps should I follow.

Answer 1

For example here is a script I use within Photoshop Actions to save and restore the users foreground and background colors so the action can mess with Photoshops foreground and background colors during its processing.
SaveAndRestoreColors.jsx
/* ======================================================================================
// 2009  John J. McAssey (JJMack)  http://www.mouseprints.net/
// This script is supplied as is. It is provided as freeware.
// The author accepts no liability for any problems arising from its use.
// This script is designed to be used by a Photoshop Action twice
// A good pratice to use when creating an actions that use this scipt is for the action
// not to do a save or play some other action between its two useages of this Script.
// The first time this script is used by an action Photoshops Current Forground
// and Background Colors are saved into the document's meta-data Info Instructions field.
// The second time this script used by the action the script retreives what was
// saved in the meta-data during the first usage and these colors are set.
// and the saved data is removed from the document's meta-data Info Instructions field.
// ===================================================================================== */
<javascriptresource>
<about>$$$/JavaScripts/SaveAndRestoreColors/About=JJMack's SaveAndRestoreColors.^r^rCopyright 2009 Mouseprints.^r^rRun twice script utility for action.^rNOTE:Don't play other actions between runs!^r^rFirst Run records Photoshops foreground and background swatch colors.^rSecond Run restores the recorded colors and removes the recording.</about>
<category>JJMack's Action Run Twice Utility</category>
</javascriptresource>
if (app.documents.length > 0) {
if (app.activeDocument.info.instructions.indexOf("<Colorf>") == -1 ){ // no footprint fisrt useage
//alert("first");
// Retreive Document information for Foot Print
saveforeColor = new SolidColor;
saveforeColor.rgb.red = app.foregroundColor.rgb.red;
saveforeColor.rgb.green = app.foregroundColor.rgb.green;
saveforeColor.rgb.blue = app.foregroundColor.rgb.blue;
savebackColor = new SolidColor;
savebackColor.rgb.red = app.backgroundColor.rgb.red;
savebackColor.rgb.green = app.backgroundColor.rgb.green;
savebackColor.rgb.blue = app.backgroundColor.rgb.blue;
// put footprint in metadata info instructions
app.activeDocument.info.instructions = app.activeDocument.info.instructions + "<Colorf>" + saveforeColor.rgb.red + "," + saveforeColor.rgb.green + "," + saveforeColor.rgb.blue + "</Colorf>" + "<Colorb>" + savebackColor.rgb.red + "," + savebackColor.rgb.green + "," + savebackColor.rgb.blue + "</Colorb>";
//alert( "Saved ="  + "<Colorf>" + saveforeColor.rgb.red + "," + saveforeColor.rgb.green + "," + saveforeColor.rgb.blue + "</Colorf>" + "<Colorb>" + savebackColor.rgb.red + "," + savebackColor.rgb.green + "," + savebackColor.rgb.blue + "</Colorb>");
else {
//alert("second");
// Retreive saved information
colorfOffset = app.activeDocument.info.instructions.indexOf("<Colorf>") + "<Colorf>".length;
colorfLength = app.activeDocument.info.instructions.indexOf("</Colorf") -colorfOffset;
saveforeColor = app.activeDocument.info.instructions.substr(colorfOffset, colorfLength);
colorbOffset = app.activeDocument.info.instructions.indexOf("<Colorb>") + "<Colorb>".length;
colorbLength = app.activeDocument.info.instructions.indexOf("</Colorb") -colorbOffset;
savebackColor = app.activeDocument.info.instructions.substr(colorbOffset, colorbLength);
//alert("Colorf = " + saveforeColor + " Colorb = " + savebackColor );
// Restore Colors
app.foregroundColor.rgb.red = saveforeColor.substr(0,saveforeColor.indexOf(","));
saveforeColor = saveforeColor.substr(saveforeColor.indexOf(",") + 1,saveforeColor.length);
app.foregroundColor.rgb.green = saveforeColor.substr(0,saveforeColor.indexOf(","));
saveforeColor = saveforeColor.substr(saveforeColor.indexOf(",") + 1,saveforeColor.length);
app.foregroundColor.rgb.blue = saveforeColor ;
app.backgroundColor.rgb.red = savebackColor.substr(0,savebackColor.indexOf(","));
savebackColor = savebackColor.substr((savebackColor.indexOf(",") + 1),savebackColor.length);
app.backgroundColor.rgb.green = savebackColor.substr(0,savebackColor.indexOf(","));
savebackColor = savebackColor.substr(savebackColor.indexOf(",") + 1,savebackColor.length);
app.backgroundColor.rgb.blue = savebackColor ;
// Remove footprint from metadata info instructions
before = app.activeDocument.info.instructions.substr(0,app.activeDocument.info.instructions.indexO f("<Colorf>"));
afterOffset = app.activeDocument.info.instructions.indexOf("</Colorb>") + "</Colorb>".length;
after = app.activeDocument.info.instructions.substr(afterOffset, app.activeDocument.info.instructions.length - afterOffset);
//alert ("before = " + before + " after = " + after);
app.activeDocument.info.instructions = before + after;
else { alert("You must have at least one open document to run this script!"); }