Although white papers are the standard, other variants of colored papers also exist.

Yellow paper

A yellow paper is a document containing research that has not yet been formally accepted or published in an academic journal. Although the original Ethereum white paper was published by Vitalik Buterin at the beginning of 2014, towards the middle of 2014 an Ethereum yellow paper was also produced by Dr. Gavin Wood, co-founder and former chief technical officer of the Ethereum project (https://ethereum.github.io/yellowpaper/paper.pdf). It is a very technical paper and is written on a dull yellow background:

Figure 1: The Ethereum yellow paper published by Dr. Gavin Wood

Green papers

Green papers typically set out discussions or proposals which are still at a formative stage. In fact, the Oxford English Dictionary defines a green paper as (in the UK) a preliminary report of government proposals published to stimulate discussion. (https://en.oxforddictionaries.com/definition/green_paper).

The Melon project produced a green paper outlining its blockchain protocol for digital asset management, and Holo also created a green paper describing an ecosystem that relies on hosts to provide processing and storage for distributed applications, while earning redeemable credits (https://github.com/melonproject/paper/blob/master/melonprotocol.pdf):

Figure 2: The Melon project produced a green paper

White papers in the early days had certain commonalities. They were very academic in nature, had an abstract, contained complicated mathematics, and various proofs, and were generally intended for a technical audience, particularly in the fields of cryptography, distributed computing, and mathematics. This was not surprising, as consensus mechanisms involving these technical concepts were at the core of the first white papers and mathematics was required when creating a lot of these protocols.

As an example, the following equation from the original bitcoin white paper demonstrates that the probability of an attacker attempting to purchase something with bitcoin and then reversing the transaction, in what is called a "double spend attack", actually decreases exponentially over time:

Figure 3: An example of the mathematics included in the bitcoin white paper

Nxt introduced a table of contents into its white paper, which was a novelty at the time but proved really useful.

The Ethereum white paper, while still technical in nature, spent the first 12 pages providing background and explaining the challenges of bitcoin and alternative blockchain applications, before explaining what Ethereum was. It was providing context and justified Ethereum's creation, addressing various limitations of the existing systems:

"The intent of Ethereum is to merge together and improve upon the concepts of scripting, altcoins, and on-chain meta-protocols, and allow developers to create arbitrary consensus-based applications that have the scalability, standardization, feature-completeness, ease of development, and interoperability offered by these different paradigms all at the same time."

In the first half of 2016, DigixDAO, a distributed autonomous organization tokenizing gold using the Ethereum blockchain, and Waves, experimented with adding color in their white papers and removed mathematical formulas. It essentially made their white papers more user-friendly to read.

DigixDAO provided numerous colored flow charts and even included a Chinese-translated version at the end of the English version, which doubled the length of the white paper to 22 pages.

Waves introduced a full-color title page in its white paper and kept details very high level. It was only 11 pages and appeared almost too simple. Information on crowdsales, however, was provided in a separate blog post.

Very quickly, ICOs discovered that if they wanted to raise more capital, the information needed to be less technical and more appealing to a wider audience. What also helped was that with these ICOs launching on existing blockchains, a lot of the technical requirements were taken care of, hence making the papers less technical by nature.

In the latter half of 2016, FirstBlood started providing information, such as project timelines, funding breakdowns, and details of its team in a 26-page white paper. FirstBlood also detailed the token sale period and the token mechanics.

Synereo, though, stuck to its guns and produced a 65-page first-generation type white paper. Synereo raised $4.7 million and FirstBlood $5.5 million, so no useful correlation can be made from comparing these two white papers.

There was definitely a shift, though, as SingularDTV, Ark, and Golem maintained the color theme, and provided details of the token supply and distribution within the document.

Humaniq's white paper was a mixture of all three generations in one. It was very academic-looking, with mathematical formulas around its token distribution, a table of contents, colored diagrams, token details, and project timelines, along with a technical section on BioID and mobile transaction details on the Ethereum network. BAT's white paper also fell into this category.

During the madness of 2017, white papers evolved very quickly. Gnosis, in one of many white papers, took things to the next level by replacing the abstract with an "executive summary" and providing a well-thought-out structure. A summary of the main headings of the Gnosis white paper are as follows:

Note that the Gnosis white paper has since been restructured, in the latest version dated December 22, 2017, in particular removing details on the token mechanics and auction.

Not only did white papers become more businesslike, but their length grew as well. This was greatly attributed to the legal disclaimers becoming bigger and more in-depth. MobileGo added a 10-page terms and conditions section at the end of its 32-page white paper and TenX added an 11-page disclaimer at the beginning of its 51-page white paper.

LAToken had a very clear and well-presented structure in its white paper, as follows:

Some white papers were more like marketing brochures, with fancy graphics, and they were missing a lot of key details. Monaco fell into this category, with several half-page graphics of a cup of coffee next to a laptop or a person reading a newspaper in a park. When stripped of graphics, Monaco's 32-page white paper was only 11 pages and just over 5,000 words long.

Figure 4: The Monaco white paper appeared more like a marketing brochure, with half-page meaningless graphics

As we see more and more tokens fall into the securities category, white papers will again transform and become more of an investment prospectus.

Information in a typical Initial Public Offering (IPO) investment prospectus includes:

The similarities are obvious. In fact, first-generation white papers are transforming and becoming known more as technical papers or research papers because the information they contain is often very detailed. This is something that Filecoin has done with its research, producing papers such as "Proof-of-Replication," "Power Fault Tolerance", and "Research Roadmap 2017", all in conjunction with its actual white paper.

IOTA has recently revamped its website and provided several academic papers to support its Tangle technology. Papers include The Tangle, Equilibria in the Tangle, and The first glance at the simulation of the Tangle: discrete model. The titles themselves are more than enough for the average reader to push the papers into the "too hard, I'll come back later (not really)" bucket.

Writing a white paper is not as easy as many may think. It involves explaining a novel idea to a wide-ranging audience in an easy-to-understand manner. It is also important to have a team of reviewers, quite often from different disciplines, such as legal, marketing and, of course, technical to ensure each part of the white paper is correct and accurate.

There is no standard methodology for writing a white paper, but the following presents a range of sections to include when writing one. Not every section needs to be included and the terminology can be chosen as appropriate. For example, "executive summary" has become more popular than "abstract." Some ICOs use the term "allocation", while others use "distribution" or "issuance." Some have a general "advisory board" section, whereas others split it up into more detail, such as "marketing", "technology", and "legal advisors." In essence, there is no right or wrong way: