This is to raise awareness on leukaemia – a type of blood cancer.
The inaugural orange day is the initiative of the Cecilia Ali Leukaemia Foundation (CALF).
CALF has had a few sponsors on board to see to the worthy course.
"It's something we believe in, the values and especially that the funds are going towards raising awareness on blood cancers and helping people living with leukaemia," said Andrew Rumawery from SMEC.
CEO and co-founder of CALF, Christina Cragnolini, says at least 600 people are expected to show up.
The day to be held at Sir John Guise Stadium will be full of fun activities including a walk, tug-of-war, BBQ, jumping castle for the kids and face painting.
Cragnolini says this is the major fundraiser for the foundation this year.
CALF was established 3 years ago to raise awareness on leukaemia and other types of blood diseases.
"We want the public to know that blood cancers affect people of all age - babies to old people," she said.
The foundation's biggest help last year was by Winged MEA - a group of women who climbed Mt Wilhelm to raise funds for CALF and carry out mobile awareness.
To register for the Orange day, visit the Cecilia Ali Leukaemia Foundation FB page; K40 for individuals and K1000 for corporate bodies.