uxday
Logo designed for uxday (www.uxday.it), a conference about User Experience organised by Apropos srl and GrUSP in Faenza, Italy.
This is the procedure I used to design the logo with just one sign. I chose two colours: a dark green (#1A5F5D) and a warm yellow (#FFDE10). I used WebAIM Contrast Checker (https://webaim.org/resources/contrastchecker/) to be sure that the green creates good contrast on white when used for text, big or small. The yellow instead creates a good contrast when used on dark green. I then used Colour Blindness Simulator by Coblis (https://www.color-blindness.com/coblis-color-blindness-simulator/) to check that the two colours also work — that is, you can distinguish one from the other — in case of colour vision deficiencies.