ThomaTools

Thoma AG / Basel / Digital tools

PDF Colour Converter

Inspect, merge and convert PDFs online. Prepare letters and address labels with tools by Thoma AG in Basel.

Free to use. No account needed.

Quick Actions Colour Converter
Free

Colour Converter

Change the colour space in your PDF.

Drop your PDF here

or choose a file

Up to 50 MB per PDF. Pro has no upload-size limit.

    Converts the selected RGB or CMYK source colours in text, vector artwork and images. Embedded source ICC profiles are used where present. The destination is device CMYK or grey, without a selected press profile; colours may look different.

    Text and vectors remain text and vectors. The conversion includes gradients, patterns, image masks, transparency and annotation appearances. Spot inks retain their names, with their screen and composite-print alternate colours converted. Review the result before printing.

    Conversion returns a separate PDF. When an encrypted or signed source is changed, the converted copy is decrypted and unsigned; source permissions and certification no longer apply to that copy. The original stays unchanged.

    Choose a PDF to begin.

    This action sends your PDF to our server. Processing is temporary; files and results are not saved. Privacy

    Using this tool

    Convert colours in a PDF

    Choose RGB to CMYK, RGB to grey or CMYK to grey for PDF text, vector artwork and images. The selected source colour model changes throughout the document; other source colour models stay unchanged.

    1. Choose the PDF you want to convert.
    2. Select a conversion and run Convert colours.
    3. Review the preview and conversion counts, then download the separate PDF.

    Embedded source profiles are used. The destination uses device colours without a selected press profile. Use Analysis to inspect the result and check the actual print output.

    Processing happens temporarily on our server when you run a tool. We do not retain your documents, address lists or results. Read our Privacy.