I use StampinUp cardstock to create wedding invitations. I find that the rgb color chart they publish is not true to color when I print in Word or pdf from my HP laptop to my HP printer. I took one page to Staples on a flash drive to print and the color was right. What am I doing wrong?
You can use RGB colors codes as input in softwares like PS but you should be either working in CMYK mode or save the final file in CMYK mode to get the desired colors for printing.
RGB (Red-Green-Blue) is the color of the light emitted from your computer monitor, and from TV's. Use RGB if you are taking photos specifically to be viewed onscreen, such as the internet, or for a CD or emails. RGB usually also works well for printing from your home or office printer.
CMYK (Cyan, Magenta, Yellow, Black) is the color of inks used in the offset printing process. Use CMYK if you are sending your photo to be printed, such as preparing a postcard to be professionally printed for a gallery invite.