Color Picker - where to insert a color code?

background: #30E8BF; /* fallback for old browsers */
background: -webkit-linear-gradient(to bottom, #FF8235, #30E8BF); /* Chrome 10-25, Safari 5.1-6 */
background: linear-gradient(to bottom, #FF8235, #30E8BF); /* W3C, IE 10+/ Edge, Firefox 16+, Chrome 26+, Opera 12+, Safari 7+ */+

#gjsuu

A couple of comments :

You colour picker should look like this :

If it does not go to Preferences > General and make sure that the colour picker is set to Adobe

Now an extra note of warning. When you enter a colour as Hex Values - those values will only give the same colour as the specified colour when you are working in the same colour space (i.e. your document has exactly the same colour profile as used when the numbers were specified). The same hex numbers with different profiles will give different colors.

Dave