From Web CPA:

Changes should be made in the layout and typeface of 1040 individual tax forms, including more use of boldface, colors and explanations, to help reduce taxpayer errors, recommends a new government report. The Treasury Department’s Inspector General for Tax Administration noted in the report that each year, the IRS sends out more than 7 million math error notices informing taxpayers of mistakes in their tax returns. More than 2.3 million of those errors could have resulted from unclear or inadequate forms, TIGTA noted. An analysis of taxpayer errors on 2005 tax returns identified three areas where modifying the 1040 and its instructions could reduce errors. These included errors made computing the deduction for personal tax exemptions; the omission of dependent Social Security numbers or Individual Taxpayer Identification Numbers; and children claimed for the Child Tax Credit who exceeded the age limit. …

TIGTA also recommended that the IRS seek congressional approval to use additional colors on tax returns and instructions to highlight important warnings and information. Congressional approval would be needed because the IRS used multiple colors on the cover of of its 1995 tax packet and received some negative publicity. After that happened, Congress mandated in the Treasury Department Appropriations Act of 1997 that the IRS could use only two ink colors on tax packages. …

The IRS did not comment on the color recommendation, but noted that matters of tax policy are within the jurisdiction of the Treasury Department's Office of Tax Policy, and a copy of the report will be forwarded to that office. However, IRS management agreed to conduct a review of where it could more effectively use shading, bolding, and other changes such as font sizes on the 1040 to highlight the most important areas.