What is the difference between CMYK and Pantone? When Pantone is recommended in design and when CMYK?
I have a logo which is using C(Blue) 100% and I need its Pantone code, But unable to find it online or in illustrator.
Pantone colours include a wider range than CMYK. The range of CMYK is limited by what can be achieved by combining four colours of pigment, and while those four colours provide a good range of colours, colours outside of that range can be achieved with different pigments. Pantone specifies as wide a range of colours as possible, not limited to CMYK. CMYK values are also less accurate, as interaction between the pigments produces more variation. Specifying a Pantone colour would always be more accurate, but if the result is going to be printed using CMYK process, then the CMYK value is what you will actually get, so you might as well use that to have a better idea what the result will actually be.
As I understand in practice it is very difficult to predict the exact result, there is a lot of expert knowledge in colour printing.
Pantone lists a colour called "PMS Process Cyan" which I understand to mean "Cyan used in CMYK printing process". There is also a "PMS Process Magenta" and "PMS Process Yellow". Actual pigments will vary, but Pantone PMS Process Cyan was a fairly good match to the two printing inks I measured, so I would start with that.
Pantone is a custom ink provider. You would use pantone colos if you plan to print with custom colors (called spot colors).
100% Cyan color is not defined. CMYK is a device specific colorspacez in to know how to convert it to same pantone color or the color on any other printer we need to know what CMYK color profile you are using.