We do not provide a colour management or colour-matching service. We provide a digital printing service, and variances in colours can occur as a result.
However, please save your artwork in CMYK for greater control over the colour production. (Example Profile to use PDF/x-1a Coated FOGRA39).
If your file's colour setting is saved as RGB, the colour production is likely to be affected, because the file will be converted to CMYK.
Please also note that computer screens display colours in RGB but we print in CMYK, so there will always be a slight difference in what you receive versus what you see on your screen.