The Best Part Of Me

King Here
Hello there! First of all, the main idea of this writing was kind of odd and unattractive at least for me because of the strange basic thing we are talking about which is the fact that human has hands. If we drop that and leave it aside, I think you had wrote it well even if it could be even twice better. I see that you are a new member so I want to say welcome to the site before I forget to do so. I hope you have fun in this site and you find many nice people to connect with who will help you in the future. There are surely a lots here. Now, for the things that I think can be corrected.

The color is also white

I think you do not have to use 'also' here because we talk about one thing, the hand, and we do not compare it with something else or say it has the same color. We talk about the color for the first time. I think I can help you with this problem.
Example:
A: I love blue! It is my favourite color!
B: Really? Mine also!
If you had talked about this previously, you can use 'also'.
We use when we talk about one thing and we say different things for that object or subject.
You can not say 'the color' is white. 'The hand' is the one being white. We talk about the hands of yours in the poem so think about them.

It is pale and makes it bright in the light

'make it bright in the light' it makes no sense here for me. It looks like you had forgotten something. You can not 'make it bright' but you can make it 'look bright'.

And it is white just like frost

This is actually more like a suggestion and an advice for you.
Do not start sentence and new lines with 'and' or 'but', or connective/seperating words like these ones. It does not sound well and it is something I understood recently. I would delete the whole 'And it is' part.

When I am older and tall I could play basketball

You have messed up the tense in this line.
'I am' and 'I could'
If you use 'are' which is present simple tense, you can not continue with past tense.
This is the way it is. You can not be in the present and in the past at the same time in such a situation. Change the whole line. Even if we correct the tense, it still does not make any sense because you get older and taller and you continue to get older.
It is the best for this line to be in future tense or to be changes wholy into a present tense sentence.
Corrections choices:
When I grow older and taller I will be able to play basketball
or
When I grew older and taller I could play basketball

The best part of me is my hand

'hand' needs to be 'hands', I suppose? We have two hands and they are identical.


Good job and keep on working and writing.