To many of us the term "Colours" means the banners carried by an infantry battalion, adorned with the Battle Honours they have gained in days gone by.
However, "Colours" is also used in military terminology to represent the time a soldier served with a Regiment.
Prior to the war that was to come, men signed on for 12 years service "with the Colours" which could be divided into a number of options for time serving with a Battalion at home or abroad or on the reserve list - ready to be called upon in times of national emergency.
Normally men would serve 7 years with the Colours and 5 years on the reserve, but they could change this for 3 years with the Colours and 9 on the reserve, or alternatively, they could opt to serve to 12 years straight, and promotion to the rank of sergeant could only be obtained if you had served the entire 12 year-period in one stretch.
The 2nd Battalion was running at approx. 590 all ranks in April 1914, but at the drop of a hat, a further 400 men could be called up in a number of hours...

When 2nd Suffolk were stationed in Ireland in 1914, their primary working dress was khaki. 
However as a Home Service Battalion, their headdress would have included the distinctive blue cloth spiked helmet. 
Normally, it would have been worn with the scarlet frock and dark blue trousers on 'high days and holidays' but it was also to be worn as part of the khaki working dress if the situation arose. 
In the troubled days following the affair at the Curragh, it is highly probably that Lieut-Col. Brett, may have ordered its wearing, especially should they have been asked to proceed against Ulster - if for no other reason that to look a bit more menacing! 
Seen above two years before, Private Middleton is on guard at Brinkinault Colliery, Chirk, wearing the imposing spiked Home Service helmet. Perhaps it's appearance did the trick. The strike resided and the men returned to work an few days after 2nd Suffolk arrived. Ludicrous and impracticable you might say, but the enemy that they were soon to face also wore spiked hats!