How to customize reCaptcha default image

Hi,Could you please let me know whether we can override the default image (http://bit.ly/1zCNF9J) displayed in Google reCaptcha with own image? I this below image color is blue. I want to change it to red.Thanks,Surya -- You received this message because you are subscribed to the Google Groups "reCAPTCHA" group. To unsubscribe from this group and stop receiving emails from it, send an email to recaptcha+unsubscribe@googlegroups.com. To post to this group, send email to recaptcha@googlegroups.com. Visit this group at http://bit.ly/1dkFnYd. For more options, visit http://bit.ly/P65DvS.