This video Darren teaches you the "north" and "south" variations of colours.
Towards the end of the video there are some handy ways to remember them. For example, RED - point at your lips. ORANGE - mime eating a carrot, and so forth. When you need to remind a student (or yourself) you say 'lips' or 'carrot' as a prompt.
See the attached PDF for a list of signs taught in this video.
As a classroom activity l love playing a game with students where l sign:
"WHERE BLUE BOX" - The sign for "box" may not have been taught yet but it is visual and then all the children have to quickly (walk not run!!) find a blue box.
Then they come back and l will sign..."where red..." (fire extinguisher - which again is very visual in pulling the pin and spraying it around).
This game works wonderfully well even in Foundation.
Another way to play this activity is to divide the students into lines of 2 or 3 then sign "WHERE ORANGE FOOD? (again, "food" can be signed visually by miming eating) and those at the front of the line have to find the orange food (maybe a student has one on the table). The rest of the children in the line cannot tell or point or help.
The student from line A, B (or C) is given a point that correctly finds / identifies the object.