For practical purposes soil texture can be assessed by hand using the method outlined in the Appendix of RB209. This method relies on the use of water.
By the application of “enough water” you can “denature” the soil to determine its texture. The action of kneading or rolling the ball of soil in your hand is very similar to running a tractor, drill or other implement over the soil. By applying pressure (force) you are changing the structure of the soil and by the application of “enough water” you speed or ease the process.
Soil compaction occurs when soil particles are pressed together, reducing pore space between them, such soils contain few large pores, less total pore volume and, consequently, a greater density.
A compacted soil has a reduced rate of both water infiltration and drainage. This happens because large pores more effectively move water downward through the soil than smaller pores.
What we see today, too much water, a clay soil with a slow percolation rate, and machinery in the field turning and turning again on the headlands.
Maybe the colour of the drill has nothing to do with it. Maybe it’s the fact that if conditions are not suitable we should not be in the field and, if we are, maybe all we need to do is not turn so many times on the headland?