Column to have fixed texts/numbers for selection

Hi,

i have an excel file with many users who feed in the data.

for example, in the column of "Color" for the color "Brick Red", some might type B/RED, other might type Brik Red, or BRICK RED.....

In short, there no uniformity, hence its difficult to filter out correct things (in this case colours).

Same thing happens in other columns also like column for "type", some may type Pipe 1/2", others may type Pipes 1/2', and others may type PIPE 0.5".

But if these columns had predefined words in them for the user to select them, then this problem can be over.

Example, for the column of "Color" having to choose drop down list,

Brick Red
Light Blue
Charcoal Grey
Dark Green
Sky Blue
Custom


and for the column of "Size (in inches)"

1/2
3/4
1
1 1/4
1 1/2
Custom

Can anybody help me to solve this problem ?