Using 'text' transformation with ImageMagick? doesn't set the color of the written text.
The following patch resolved this issue:
*** sfImageTextImageMagick.class.php 2012-02-16 23:49:04.447653096 +0100
--- sfImageTextImageMagick.class.php.new 2012-02-16 23:49:00.827727135 +0100
***************
*** 232,237 ****
--- 232,238 ----
$draw = new ImagickDraw();
$draw->setFont($this->font_dir . '/' . $this->font . '.ttf');
$draw->setFontSize($this->size);
+ $draw->setFillColor(new ImagickPixel($this->getColor()));
$resource->annotateImage($draw, $this->x, $this->y, $this->angle, $this->text);