Grey, green and white PP-R pipe are the same product standard in three different jackets. ISO 15874-2:2013, the pipe part of the PP-R family, lists eight items a pipe must be marked with, and colour is not one of them. There is no international colour code for PP-R, and no clause anywhere in the family that ties a colour to a pressure rating or a temperature limit.
What colour does carry is commercial information: which product line a maker is selling, and what a buyer asked for last time. Know that before you specify a colour, because a colour written into a purchase order without the marking clause behind it is a preference, and no supplier can be held to it.
Key Takeaways
- ISO 15874-2:2013 Table 12 sets eight minimum marking items. Colour is absent from all eight.
- Colour appears in only two clauses: print must contrast with the pipe (10.1), and colour variation is permitted (5.1).
- DIN 8077 is a dimensions standard and DIN 8078 a quality and testing standard. Neither is a colour standard.
- Three of the four suppliers checked — in Central Europe, Turkey and the UAE — publish no colour attribute at all. The German one uses colour as its own product-line label.
- Colour carries no UV protection. PPI TR-18 gives every pigmented non-black PP the same three-month outdoor limit.
- ASME A13.1 is about identifying installed piping, not about the body colour of a pipe product.
What ISO 15874 actually requires a PP-R pipe to carry
Clause 10.2 of ISO 15874-2:2013 is one sentence long: the minimum required marking of the pipe is specified in Table 12. That table is the whole obligation. Eight rows, an example against most of them, and a pipe carrying all eight is compliant whatever colour it is.
Two rows are worth pausing on. Application class with operating pressure, printed as Class 1/10 bar, tells you what the pipe is for, and it is the row buyers most often skip in favour of the PN number. Opacity appears only if the manufacturer declares it. Diameter and wall thickness appear together as one item, printed as 16 × 2,2 mm. ISO records edition 2 as last reviewed and confirmed in 2023, so the table is current.
| Marking item (ISO 15874-2:2013, Table 12) | Marking or symbol | What it settles for a buyer |
|---|---|---|
| Number of this International Standard | ISO 15874 | Which product standard is being claimed |
| Manufacturer’s name and/or trade mark | Name or code | Who is answerable for the batch |
| Nominal outside diameter and wall thickness | e.g. 16 × 2,2 | The dimension pair, not the PN alone |
| Pipe dimension class | e.g. A | Which tolerance table applies |
| Material | e.g. PP-R | The grade, stated by the maker |
| Application class with operating pressure | e.g. Class 1/10 bar | The service condition the pipe is rated for |
| Opacity, if declared | e.g. opaque | Optional, and often absent |
| Manufacturer’s information | Production period, site code | Traceability back to a run |
If you want the class figures behind that sixth row, our explainer on EN ISO 15874 service classes works through the temperature and time profiles each class stands for.
The two clauses where colour does appear
Saying a standard is silent invites the reader to check, so here is the check. The full 26-page text of ISO 15874-2:2013 was converted to plain text and searched: “colour” appears three times, while “color”, “pigment” and “masterbatch” appear zero times. Two clauses account for all three hits.
Clause 10.1 says that if printing is used, the colouring of the printed information shall differ from the basic colouring of the pipe. That is a legibility rule about contrast, and it is the only requirement in the document that touches colour at all. Clause 5.1, on appearance, goes the other way: slight variations in appearance of the colour are permitted. The same standard that pins wall thickness down to 0,1 mm explicitly declines to pin the colour down.
Nor does help arrive from the neighbouring parts. ISO 15874-1:2013 runs scope, normative references, terms, classification of service conditions, material and system performance. ISO 15874-5:2013 has one substantive clause, fitness for purpose of the joints and the piping system, and its seven subclauses are all tests: internal pressure, bending, pull-out, thermal cycling, pressure cycling, leak tightness under vacuum. Neither clause list contains a marking clause, let alone a colour one.
Grey, green and white: what the colour is tracking
If the standard does not set the colour, something else does. What suppliers in each export market publish answers that, and the answer is not a regional rule.
A German maker uses colour as its own product-line legend. aquatherm publishes green as approved for potable water, food-grade work and NFPA 13D sprinkler systems. Blue covers non-steam mechanical work such as hydronic heating and condenser water, and lilac runs the same 1/2 in to 18 in range as green. Its FAQ explains that the stripes identify intended use, cold against hot, and whether the pipe carries a faser layer. That legend is one company’s, for that company’s product.
Move east and the colour disappears from the paperwork. The English catalogue of Wavin Ekoplastik, one of the largest PP-R ranges in Central Europe, was converted to text and searched: across 123,838 characters, the words grey, gray, green, white, colour and color appear zero times. The range is organised by pipe series S and by application, and the same company’s labelling page gives the marking format as application class over service pressure — Class 1/10bar, 2/10bar, 4/10bar, 5/8bar — without mentioning colour.
Turkey reads the same way. Firat lists TS 9937, TSE EN ISO 15874, DIN 8077, DIN 8078 and DVGW W544 against its PPRC range. Its catalogue tables for PN 10, PN 16, PN 20 and PN 25 carry four columns each — code, outside diameter, wall thickness, length — with no colour column. Colour appears only as an “Available Colours” swatch on the fittings pages, behaving as a selectable option. In the Gulf the emphasis shifts to credentials: a UAE supplier page leads with ISO 15874, DIN 8077, DIN 8078, DVGW, SKZ, NSF 14, NSF/ANSI 61 and WRAS, and never mentions colour.
| Circulating claim | Source checked | What that source says | Verdict |
|---|---|---|---|
| ISO 15874 mandates colour stripes and stripe spacing | ISO 15874-2:2013, cl. 10.1 and 10.2 | Eight marking items, none of them colour; one contrast rule | No such requirement |
| White is the European standard colour | DIN 8077:2008-09 and DIN 8078:2008 titles | Dimensions; general quality requirements and testing | No colour standard exists |
| Green pipe resists sunlight better | PPI TR-18 (2019), clause 5.0 | All pigmented non-black PP: three months outdoors | Colour is not the variable |
| There is a pipe colour code standard | ASME A13.1-2026 scope | Identification of installed aboveground piping | True, but a different object |
Why “green resists UV” does not survive its own source
The most durable colour claim in this market is that green pigment buys weathering resistance. Clause 5.0 of PPI TR-18 settles it in one category name. Pigmented non-black polypropylene, it says, has a limited life when stored outdoors, and outdoor storage should be limited to a total of three months unless the pipe is covered or otherwise protected from sunlight. Green, white and grey PP-R all sit inside that one phrase, and share that one figure between them.
What does change the number is formulation, not appearance. The same clause credits carbon black, at 2 % to 3 % with good dispersion, or an outer layer carrying it. Chemical stabiliser packages do similar work. None of that is visible, and the first sign that it was missing is cosmetic: TR-18 describes the opening symptom of weathering as a slight discoloration of the pigment, a chalky surface or whitening, followed by loss of tensile strength and ductility. Our longer treatment of PP-R and outdoor exposure works through what to ask a supplier for instead.
The colour standard people are quoting by mistake
Buyers who insist they have seen a pipe colour standard are usually right, and looking at the wrong object. ASME A13.1, Scheme for the Identification of Piping Systems, current edition A13.1-2026, describes requirements for the identification of aboveground piping used in industrial, commercial, transmission, distribution and institutional installations, and in buildings used for public assembly. It establishes a common system for identifying the fluids conveyed and their characteristics, and it does not apply to electrical conduits.
That is a scheme for labelling pipework once installed, using legends and colour fields applied on site. It says nothing about the colour a 63 mm PP-R pipe is extruded in, and an A13.1 marking sits on top of whatever the pipe already is. The distinction matters commercially: a specifier can require A13.1 identification on a project and still have no basis to reject a delivery for being the wrong colour.
For importers and private-label buyers settling a print legend: the range, sizes and marking are on the PP-R page.
What to put on the purchase order instead
A colour line on its own is unenforceable: nothing in the product standard defines what a correct colour would be. The marking clause is enforceable, because it defines exactly what has to be legible on the pipe. Write the eight items of Table 12 in as the print legend, and treat colour as a separate cosmetic line agreed at sample stage.
In practice: name the standard number, the dimension pair rather than the PN alone, the dimension class, the material designation, the application class with operating pressure, and the traceability block. Ask for a photograph of the print line on the size you are buying, not a catalogue rendering. If colour matters to your market, state it as a finish requirement against an agreed reference sample, and remember that clause 5.1 permits slight variation, so a shade tolerance has to be agreed rather than assumed.
A private-label order differs from a stock purchase here. Buying your own colour is buying a masterbatch decision that has to repeat across runs, which is a supplier capability question, not a standards one. Hitze’s PP-R range runs OD 20 to 110 mm in standard, fibre-reinforced, aluminium-composite and copper-lined forms. It is documented against DIN 8077/8078 and EN ISO 15874, with SKZ testing on the pressure pipe and fittings; the PP-R pipe and fittings range shows size and marking before a colour is agreed. There is no minimum order quantity, so a colour can be proven on a sample run — our sample approval checklist and private-label guide cover what to fix in writing.
Conclusion
Three checks turn a colour argument back into a specification. Ask which clause of which standard the colour claim comes from; if the answer is ISO 15874, ask for the clause number, because Table 12 has eight rows and none of them is colour. Ask what the pipe is marked with, and require the application class with operating pressure in the form Class 1/10 bar, not a bare PN figure. Then, if the run will see daylight, ask what protects it and accept only a formulation or covering answer.
Colour still has a job in a catalogue, a warehouse and a brand. In a compliance argument it has none.
Frequently Asked Questions
Is there an international colour code for PPR pipe?
No. ISO 15874-2:2013 lists eight minimum marking items in Table 12 and colour is not among them. The only colour requirement in the standard is that printed information must contrast with the pipe body, under clause 10.1.
What is the difference between green, white and grey PPR pipe?
Under the product standard, nothing. The colour reflects a manufacturer’s product line and what buyers in a market have historically ordered. Pressure rating, temperature class and wall thickness are read from the printed marking, never from the colour.
Do DIN 8077 and DIN 8078 set a PPR pipe colour?
No. DIN 8077:2008-09 is titled Polypropylene (PP) pipes – PP-H, PP-B, PP-R, PP-RCT – Dimensions, and DIN 8078:2008 covers general quality requirements and testing. Neither is a colour specification.
Does pipe colour affect UV resistance?
No. PPI TR-18 (2019) treats all pigmented non-black polypropylene as one category and limits it to three months of outdoor storage unless covered. Weathering resistance comes from carbon black at two to three percent, a covering layer or a stabiliser package.
Can I reject a delivery because the pipe is the wrong colour?
Only if colour was agreed as a contractual finish requirement with a reference sample. It is not a conformity issue under ISO 15874, and clause 5.1 permits slight variations in colour appearance, so a shade tolerance has to be agreed in advance.
