Please check your artwork very carefully, especially grammar, spelling, layout and composition.
When you agree your artwork, this commits your job for printing, it can not be changed after this.
Viewing your artwork on mobile devices is not recommended.
It is unlikely that you are using calibrated screens to view your artwork. Colours on your mobile, tablet, laptop or computer monitor screen uses 3 colours of light, Red, Green & Blue to form an image, these will not match printers that use Cyan, Magenta, Yellow and Black to form an image.
If you do not own a colour calibrated screen and the finished colour output needs to match a specific range of colours, it is advisable that you get a sample print before you commence or pay for a colour matching service.