The Union Flag combines a red upright cross, white and red diagonal saltires, and a blue field. The 3:5 version shown here is the College of Arms form approved for most uses on land.
Specification
The proclamation of 1 January 1801 describes the flag heraldically: the saltires associated with St Andrew and St Patrick are quartered and counterchanged, with the red saltire edged in white, and the red cross associated with St George is also edged in white above them. The proclamation does not prescribe a single ratio.
Display colors
HEX #012169 / asset screen valueHEX #C8102E / asset screen valueHEX #FFFFFF / RGB 255, 255, 255Construction notes
The diagonal red saltire is deliberately offset within its white field. At the upper hoist, the broad white diagonal lies above the red diagonal; reversing that relationship displays the flag upside down. A symmetric red diagonal cross is therefore not a faithful construction.
Historical record
The present composition dates from 1801, when the union with Ireland led to the addition of the red saltire associated with St Patrick to the earlier union design. The College of Arms now publishes approved 3:5 and 1:2 versions for convenient standard use.
Source trail
Understanding the orientation
The hoist is the edge nearest the flagpole; a saltire is a diagonal cross. View the flag with the flagpole and hoist on your left. In the upper-left corner, the broad white diagonal lies above the red diagonal. Reversing that relationship displays the flag upside down. The red diagonal cross is deliberately offset within the white diagonals, rather than centered.
What the display colors mean
The listed HEX and RGB values describe the displayed asset. This qualification applies to blue, red and white, including white’s #FFFFFF / RGB 255, 255, 255. These are screen approximations, not a universal production standard. The supplied record notes that the 1801 proclamation fixes neither proportions nor colors: its heraldic description should not be read as a numerical color specification. Official specifications, customary manufacturing choices and screen approximations are distinct; the displayed values do not establish an official physical color standard or a manufacturing convention.