feat: support 256 colors

resolves #2429

src/color/colors.go

@@ -3,6 +3,7 @@ package color
 import (
 	"fmt"
 	"oh-my-posh/environment"
+	"strconv"
 
 	"github.com/gookit/color"
 )
@@ -78,10 +79,14 @@ func (d *DefaultColors) AnsiColorFromString(colorString string, isBackground boo
 		return colorFromName
 	}
 	style := color.HEX(colorString, isBackground)
-	if style.IsEmpty() {
-		return emptyAnsiColor
+	if !style.IsEmpty() {
+		return AnsiColor(style.String())
 	}
-	return AnsiColor(style.String())
+	if colorInt, err := strconv.ParseInt(colorString, 10, 8); err == nil {
+		c := color.C256(uint8(colorInt), isBackground)
+		return AnsiColor(c.String())
+	}
+	return emptyAnsiColor
 }
 
 // getAnsiColorFromName returns the color code for a given color name if the name is

themes/schema.json

@@ -17,7 +17,7 @@
     },
     "color_string": {
       "type": "string",
-      "pattern": "^(#([a-fA-F0-9]{6}|[a-fA-F0-9]{3})|black|red|green|yellow|blue|magenta|cyan|white|default|darkGray|lightRed|lightGreen|lightYellow|lightBlue|lightMagenta|lightCyan|lightWhite|transparent|parentBackground|parentForeground|background|foreground|accent)$",
+      "pattern": "^(#([a-fA-F0-9]{6}|[a-fA-F0-9]{3})|^([0-9]|[1-9][0-9]|1[0-9][0-9]|2[0-4][0-9]|25[0-5])$|black|red|green|yellow|blue|magenta|cyan|white|default|darkGray|lightRed|lightGreen|lightYellow|lightBlue|lightMagenta|lightCyan|lightWhite|transparent|parentBackground|parentForeground|background|foreground|accent)$",
       "title": "Color string",
       "description": "https://ohmyposh.dev/docs/configuration/colors",
       "format": "color"

website/docs/configuration/colors.mdx

@@ -17,6 +17,8 @@ Oh My Posh supports multiple different color references, being:
   as well as 8 extended ANSI colors:
 
   `darkGray` `lightRed` `lightGreen` `lightYellow` `lightBlue` `lightMagenta` `lightCyan` `lightWhite`
+- 256 color palette using their number representation.
+  For example `0` is black, `1` is red, `2` is green, etc.
 - The `transparent` keyword which can be used to create either a transparent foreground override
   or transparent background color using the segment's foreground property.
 - The `foreground` keyword which can be used to reference the current segment's foreground color.