Using Colours

When I have been making my logos and websites, I haven't been using the best colours to go together so would say. Personally I think they look fine but it's all a matter of opinion.

This is the colour wheel, what a lot of people say is that the colours opposite of each other always work together, E.G. Purple and Yellow, L.A Lakers basketball team, those colours work perfectly together, the same with blue and orange E.G. Irn-Bru. I think they work together but green and red, I only think they work together with certain things. I will also be talking about two different colour processors, one being RGB and the other being CMYK. RGB is Red, Yellow, Blue and this is used on computers to make an image that isn't going to be printed off so making a logo in Photoshop will be saved as RGB where as if you wanted to make an image that would be printed off, you would use CMYK and this stands for cyan, magenta, yellow, key. 

A colour model that describes each colour in terms of thequantity of each secondary colour (cyan, magenta, yellow), and"key" (black) it contains. The CMYK system is used for printing.For mixing of pigments, it is better to use the secondary colours,since they mix subtractively instead of additively. The secondarycolours of light are cyan, magenta and yellow, which correspondto the primary colours of pigment (blue, red and yellow). In addition, although black could be obtained by mixing these threein equal proportions, in four-colour printing it always has its ownink. This gives the CMYK model. The K stands for "Key' or 'blacK,'so as not to cause confusion with the B in RGB. 
Alternative colour models are RGB and HSB. I now understand how to mix and blend colours and I will be showing this with the next logo that i make.