Hello can you read this ?

Hello can you read this  Is is easy to read even in white?

...if it is Larger?
Hello can you read this  Is is easy to read in white?

if it is larger and yellow and bold?
Hello can you read this  Is is easy to read  in white? Hello can you read this  Is is easy to read  in white? Hello can you read this  Is is easy to read  in white? Hello can you read this  Is is easy to read  in white? Hello can you read this  Is is easy to read  in white?

Or is this background just not the best choice?